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11186 KiB

Open AccessArticle

Overexpression of the Transcription Factors GmSHN1 and GmSHN9 Differentially Regulates Wax and Cutin Biosynthesis, Alters Cuticle Properties, and Changes Leaf Phenotypes in Arabidopsis

by Yangyang Xu, Hanying Wu, Mingming Zhao, Wang Wu, Yinong Xu and Dan Gu

Int. J. Mol. Sci. 2016, 17(4), 587; https://doi.org/10.3390/ijms17040587 - 21 Apr 2016

Cited by 26 | Viewed by 8039

Abstract

SHINE (SHN/WIN) clade proteins, transcription factors of the plant-specific APETALA 2/ethylene-responsive element binding factor (AP2/ERF) family, have been proven to be involved in wax and cutin biosynthesis. Glycine max is an important economic crop, but its molecular mechanism of wax biosynthesis is rarely [...] Read more.

SHINE (SHN/WIN) clade proteins, transcription factors of the plant-specific APETALA 2/ethylene-responsive element binding factor (AP2/ERF) family, have been proven to be involved in wax and cutin biosynthesis. Glycine max is an important economic crop, but its molecular mechanism of wax biosynthesis is rarely characterized. In this study, 10 homologs of Arabidopsis SHN genes were identified from soybean. These homologs were different in gene structures and organ expression patterns. Constitutive expression of each of the soybean SHN genes in Arabidopsis led to different leaf phenotypes, as well as different levels of glossiness on leaf surfaces. Overexpression of GmSHN1 and GmSHN9 in Arabidopsis exhibited 7.8-fold and 9.9-fold up-regulation of leaf cuticle wax productions, respectively. C31 and C29 alkanes contributed most to the increased wax contents. Total cutin contents of leaves were increased 11.4-fold in GmSHN1 overexpressors and 5.7-fold in GmSHN9 overexpressors, mainly through increasing C16:0 di-OH and dioic acids. GmSHN1 and GmSHN9 also altered leaf cuticle membrane ultrastructure and increased water loss rate in transgenic Arabidopsis plants. Transcript levels of many wax and cutin biosynthesis and leaf development related genes were altered in GmSHN1 and GmSHN9 overexpressors. Overall, these results suggest that GmSHN1 and GmSHN9 may differentially regulate the leaf development process as well as wax and cutin biosynthesis. Full article

(This article belongs to the Special Issue Molecular Research in Plant Secondary Metabolism 2015)

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4907 KiB

Open AccessArticle

Cloning and Characterization of a Flavonoid 3′-Hydroxylase Gene from Tea Plant (Camellia sinensis)

by Tian-Shan Zhou, Rui Zhou, You-Ben Yu, Yao Xiao, Dong-Hua Li, Bin Xiao, Oliver Yu and Ya-Jun Yang

Int. J. Mol. Sci. 2016, 17(2), 261; https://doi.org/10.3390/ijms17020261 - 22 Feb 2016

Cited by 38 | Viewed by 8268

Abstract

Tea leaves contain abundant flavan-3-ols, which include dihydroxylated and trihydroxylated catechins. Flavonoid 3′-hydroxylase (F3′H: EC 1.14.13.21) is one of the enzymes in the establishment of the hydroxylation pattern. A gene encoding F3′H, designated as CsF3′H, was isolated from Camellia sinensis [...] Read more.

Tea leaves contain abundant flavan-3-ols, which include dihydroxylated and trihydroxylated catechins. Flavonoid 3′-hydroxylase (F3′H: EC 1.14.13.21) is one of the enzymes in the establishment of the hydroxylation pattern. A gene encoding F3′H, designated as CsF3′H, was isolated from Camellia sinensis with a homology-based cloning technique and deposited in the GenBank (GenBank ID: KT180309). Bioinformatic analysis revealed that CsF3′H was highly homologous with the characterized F3′Hs from other plant species. Four conserved cytochrome P450-featured motifs and three F3′H-specific conserved motifs were discovered in the protein sequence of CsF3′H. Enzymatic analysis of the heterologously expressed CsF3′H in yeast demonstrated that tea F3′H catalyzed the 3′-hydroxylation of naringenin, dihydrokaempferol and kaempferol. Apparent K_m values for these substrates were 17.08, 143.64 and 68.06 μM, and their apparent V_max values were 0.98, 0.19 and 0.44 pM·min⁻¹, respectively. Transcription level of CsF3′H in the new shoots, during tea seed germination was measured, along with that of other key genes for flavonoid biosynthesis using real-time PCR technique. The changes in 3′,4′-flavan-3-ols, 3′,4′,5′-flavan-3-ols and flavan-3-ols, were consistent with the expression level of CsF3′H and other related genes in the leaves. In the study of nitrogen supply for the tea plant growth, our results showed the expression level of CsF3′H and all other tested genes increased in response to nitrogen depletion after 12 days of treatment, in agreement with a corresponding increase in 3′,4′-catechins, 3′,4′,5′-catechins and flavan 3-ols content in the leaves. All these results suggest the importance of CsF3′H in the biosynthesis of 3′,4′-catechins, 3′,4′,5′-catechins and flavan 3-ols in tea leaves. Full article

(This article belongs to the Special Issue Molecular Research in Plant Secondary Metabolism 2015)

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3166 KiB

Open AccessArticle

Investigation of the Antiproliferative Properties of Natural Sesquiterpenes from Artemisia asiatica and Onopordum acanthium on HL-60 Cells in Vitro

by Judit Molnár, Gábor J. Szebeni, Boglárka Csupor-Löffler, Zsuzsanna Hajdú, Thomas Szekeres, Philipp Saiko, Imre Ocsovszki, László G. Puskás, Judit Hohmann and István Zupkó

Int. J. Mol. Sci. 2016, 17(2), 83; https://doi.org/10.3390/ijms17020083 - 17 Feb 2016

Cited by 18 | Viewed by 6547

Abstract

Plants and plant extracts play a crucial role in the research into novel antineoplastic agents. Four sesquiterpene lactones, artecanin (1), 3β-chloro-4α,10α-dihydroxy-1α,2α-epoxy-5α,7αH-guaia-11(13)-en-12,6α-olide (2), iso-seco-tanapartholide 3-O-methyl ether (3) and 4β,15-dihydro-3-dehydrozaluzanin C (4), were isolated from two [...] Read more.

Plants and plant extracts play a crucial role in the research into novel antineoplastic agents. Four sesquiterpene lactones, artecanin (1), 3β-chloro-4α,10α-dihydroxy-1α,2α-epoxy-5α,7αH-guaia-11(13)-en-12,6α-olide (2), iso-seco-tanapartholide 3-O-methyl ether (3) and 4β,15-dihydro-3-dehydrozaluzanin C (4), were isolated from two traditionally used Asteraceae species (Onopordum acanthium and Artemisia asiatica). When tested for antiproliferative action on HL-60 leukemia cells, these compounds exhibited reasonable IC₅₀ values in the range 3.6–13.5 μM. Treatment with the tested compounds resulted in a cell cycle disturbance characterized by increases in the G1 and G2/M populations, while there was a decrease in the S phase. Additionally, 1–3 elicited increases in the hypodiploid (subG1) population. The compounds elicited concentration-dependent chromatin condensation and disruption of the membrane integrity, as revealed by Hoechst 33258–propidium staining. Treatment for 24 h resulted in significant increases in activity of caspases-3 and -9, indicating that the tested sesquiterpenes induced the mitochondrial pathway of apoptosis. The proapoptotic properties of the sesquiterpene lactones were additionally demonstrated withannexin V staining. Compounds 1 and 2 increased the Bax/Bcl-2 expression and decreased the expressions of CDK1 and cyclin B2, as determined at the mRNA level by means of RT-PCR. These experimental results indicate that sesquiterpene lactones may be regarded as potential starting structures for the development of novel anticancer agents. Full article

(This article belongs to the Special Issue Molecular Research in Plant Secondary Metabolism 2015)

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3278 KiB

Open AccessArticle

Genome-Wide Identification, Characterization and Expression Analysis of the Chalcone Synthase Family in Maize

by Yahui Han, Ting Ding, Bo Su and Haiyang Jiang

Int. J. Mol. Sci. 2016, 17(2), 161; https://doi.org/10.3390/ijms17020161 - 27 Jan 2016

Cited by 85 | Viewed by 8412

Abstract

Members of the chalcone synthase (CHS) family participate in the synthesis of a series of secondary metabolites in plants, fungi and bacteria. The metabolites play important roles in protecting land plants against various environmental stresses during the evolutionary process. Our research was conducted [...] Read more.

Members of the chalcone synthase (CHS) family participate in the synthesis of a series of secondary metabolites in plants, fungi and bacteria. The metabolites play important roles in protecting land plants against various environmental stresses during the evolutionary process. Our research was conducted on comprehensive investigation of CHS genes in maize (Zea mays L.), including their phylogenetic relationships, gene structures, chromosomal locations and expression analysis. Fourteen CHS genes (ZmCHS01–14) were identified in the genome of maize, representing one of the largest numbers of CHS family members identified in one organism to date. The gene family was classified into four major classes (classes I–IV) based on their phylogenetic relationships. Most of them contained two exons and one intron. The 14 genes were unevenly located on six chromosomes. Two segmental duplication events were identified, which might contribute to the expansion of the maize CHS gene family to some extent. In addition, quantitative real-time PCR and microarray data analyses suggested that ZmCHS genes exhibited various expression patterns, indicating functional diversification of the ZmCHS genes. Our results will contribute to future studies of the complexity of the CHS gene family in maize and provide valuable information for the systematic analysis of the functions of the CHS gene family. Full article

(This article belongs to the Special Issue Molecular Research in Plant Secondary Metabolism 2015)

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Open AccessArticle

Elicitation of Diosgenin Production in Trigonella foenum-graecum (Fenugreek) Seedlings by Methyl Jasmonate

by Spandan Chaudhary, Surendra K. Chikara, Mahesh C. Sharma, Abhinav Chaudhary, Bakhtiyar Alam Syed, Pooja S. Chaudhary, Aditya Mehta, Maulik Patel, Arpita Ghosh and Marcello Iriti

Int. J. Mol. Sci. 2015, 16(12), 29889-29899; https://doi.org/10.3390/ijms161226208 - 15 Dec 2015

Cited by 54 | Viewed by 8788

Abstract

The effects of methyl jasmonate (MeJA), an elicitor of plant defense mechanisms, on the biosynthesis of diosgenin, a steroidal saponin, were investigated in six fenugreek (Trigonella foenum-graecum) varieties (Gujarat Methi-2, Kasuri-1, Kasuri-2, Pusa Early Branching, Rajasthan Methi and Maharashtra Methi-5). Treatment [...] Read more.

The effects of methyl jasmonate (MeJA), an elicitor of plant defense mechanisms, on the biosynthesis of diosgenin, a steroidal saponin, were investigated in six fenugreek (Trigonella foenum-graecum) varieties (Gujarat Methi-2, Kasuri-1, Kasuri-2, Pusa Early Branching, Rajasthan Methi and Maharashtra Methi-5). Treatment with 0.01% MeJA increased diosgenin levels, in 12 days old seedlings, from 0.5%–0.9% to 1.1%–1.8%. In addition, MeJA upregulated the expression of two pivotal genes of the mevalonate pathway, the metabolic route leading to diosgenin: 3-hydroxy-3-methylglutaryl-CoA reductase (HMG) and sterol-3-β-glucosyl transferase (STRL). In particular, MeJA increased the expression of HMG and STRL genes by 3.2- and 22.2-fold, respectively, in the Gujarat Methi-2 variety, and by 25.4- and 28.4-fold, respectively, in the Kasuri-2 variety. Therefore, MeJA may be considered a promising elicitor for diosgenin production by fenugreek plants. Full article

(This article belongs to the Special Issue Molecular Research in Plant Secondary Metabolism 2015)

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904 KiB

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Omics-Based Comparative Transcriptional Profiling of Two Contrasting Rice Genotypes during Early Infestation by Small Brown Planthopper

by Weilin Zhang, Ling Yang, Mei Li, Bojun Ma, Chengqi Yan and Jianping Chen

Int. J. Mol. Sci. 2015, 16(12), 28746-28764; https://doi.org/10.3390/ijms161226128 - 3 Dec 2015

Cited by 12 | Viewed by 6314

Abstract

The small brown planthopper (SBPH) is one of the destructive pests of rice. Although different biochemical pathways that are involved in rice responding to planthopper infestation have been documented, it is unclear which individual metabolic pathways are responsive to planthopper infestation. In this [...] Read more.

The small brown planthopper (SBPH) is one of the destructive pests of rice. Although different biochemical pathways that are involved in rice responding to planthopper infestation have been documented, it is unclear which individual metabolic pathways are responsive to planthopper infestation. In this study, an omics-based comparative transcriptional profiling of two contrasting rice genotypes, an SBPH-resistant and an SBPH-susceptible rice line, was assessed for rice individual metabolic pathways responsive to SBPH infestation. When exposed to SBPH, 166 metabolic pathways were differentially regulated; of these, more than one-third of metabolic pathways displayed similar change patterns between these two contrasting rice genotypes; the difference of change pattern between these two contrasting rice genotypes mostly lies in biosynthetic pathways and the obvious difference of change pattern lies in energy metabolism pathways. Combining the Pathway Tools Omics Viewer with the web tool Venn, 21 and 6 metabolic pathways which potentially associated with SBPH resistance and susceptibility, respectively were identified. This study presents an omics-based comparative transcriptional profiling of SBPH-resistant and SBPH-susceptible rice plants during early infestation by SBPH, which will be very informative in studying rice-insect interaction. The results will provide insight into how rice plants respond to early infestation by SBPH from the biochemical pathways perspective. Full article

(This article belongs to the Special Issue Molecular Research in Plant Secondary Metabolism 2015)

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2418 KiB

Open AccessArticle

ClRTL1 Encodes a Chinese Fir RNase III–Like Protein Involved in Regulating Shoot Branching

by Xia Li, Qian Su, Renhua Zheng, Guangxin Liu, Ye Lu, Liming Bian, Jinhui Chen and Jisen Shi

Int. J. Mol. Sci. 2015, 16(10), 25691-25710; https://doi.org/10.3390/ijms161025691 - 26 Oct 2015

Cited by 4 | Viewed by 6576

Abstract

Identification of genes controlling shoot branching is crucial for improving plant architecture and increasing crop yield or biomass. A branching mutant of Chinese fir named “Dugansha” (Cunninghamia lanceolata var. dugan.) has been isolated in our laboratory. We chose the cDNA-AFLP technique [...] Read more.

Identification of genes controlling shoot branching is crucial for improving plant architecture and increasing crop yield or biomass. A branching mutant of Chinese fir named “Dugansha” (Cunninghamia lanceolata var. dugan.) has been isolated in our laboratory. We chose the cDNA-AFLP technique and an effective strategy to screen genes that potentially regulate shoot branching in Chinese fir using this mutant. An RNase III-like1 cDNA fragment named ClRTL1 was identified as a potential positive regulator. To investigate the function of ClRTL1 in regulating shoot branching, we cloned the full-length cDNA sequence from C. lanceolata (Lamb.) Hook, deduced its secondary structure and function, and overexpressed the coding sequence in Arabidopsis. The ClRTL1 cDNA is 1045 bp and comprises an open reading frame of 705 bp. It encodes a protein of 235 amino acids. The deduced secondary structure of the ClRTL1 indicates that it is a mini-RNase III-like protein. The expression analysis and phenotypes of 35S: ClRTL1 in A. thaliana implies that ClRTL1 plays a role in promoting shoot branching in Chinese fir. Full article

(This article belongs to the Special Issue Molecular Research in Plant Secondary Metabolism 2015)

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6512 KiB

Open AccessArticle

Molecular Cloning and Characterization of DXS and DXR Genes in the Terpenoid Biosynthetic Pathway of Tripterygium wilfordii

by Yuru Tong, Ping Su, Yujun Zhao, Meng Zhang, Xiujuan Wang, Yujia Liu, Xianan Zhang, Wei Gao and Luqi Huang

Int. J. Mol. Sci. 2015, 16(10), 25516-25535; https://doi.org/10.3390/ijms161025516 - 23 Oct 2015

Cited by 62 | Viewed by 8319

Abstract

1-Deoxy-d-xylulose-5-phosphate synthase (DXS) and 1-deoxy-d-xylulose-5-phosphate reductoisomerase (DXR) genes are the key enzyme genes of terpenoid biosynthesis but still unknown in Tripterygium wilfordii Hook. f. Here, three full-length cDNA encoding DXS1, DXS2 and DXR were cloned from suspension cells of T. wilfordii with ORF [...] Read more.

1-Deoxy-d-xylulose-5-phosphate synthase (DXS) and 1-deoxy-d-xylulose-5-phosphate reductoisomerase (DXR) genes are the key enzyme genes of terpenoid biosynthesis but still unknown in Tripterygium wilfordii Hook. f. Here, three full-length cDNA encoding DXS1, DXS2 and DXR were cloned from suspension cells of T. wilfordii with ORF sizes of 2154 bp (TwDXS1, GenBank accession no.KM879187), 2148 bp (TwDXS2, GenBank accession no.KM879186), 1410 bp (TwDXR, GenBank accession no.KM879185). And, the TwDXS1, TwDXS2 and TwDXR were characterized by color complementation in lycopene accumulating strains of Escherichia coli, which indicated that they encoded functional proteins and promoted lycopene pathway flux. TwDXS1 and TwDXS2 are constitutively expressed in the roots, stems and leaves and the expression level showed an order of roots > stems > leaves. After the suspension cells were induced by methyl jasmonate, the mRNA expression level of TwDXS1, TwDXS2, and TwDXR increased, and triptophenolide was rapidly accumulated to 149.52 µg·g⁻¹, a 5.88-fold increase compared with the control. So the TwDXS1, TwDXS2, and TwDXR could be important genes involved in terpenoid biosynthesis in Tripterygium wilfordii Hook. f. Full article

(This article belongs to the Special Issue Molecular Research in Plant Secondary Metabolism 2015)

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4746 KiB

Open AccessArticle

Stress Sensitivity Is Associated with Differential Accumulation of Reactive Oxygen and Nitrogen Species in Maize Genotypes with Contrasting Levels of Drought Tolerance

by Liming Yang, Jake C. Fountain, Hui Wang, Xinzhi Ni, Pingsheng Ji, Robert D. Lee, Robert C. Kemerait, Brian T. Scully and Baozhu Guo

Int. J. Mol. Sci. 2015, 16(10), 24791-24819; https://doi.org/10.3390/ijms161024791 - 19 Oct 2015

Cited by 40 | Viewed by 7895

Abstract

Drought stress decreases crop growth, yield, and can further exacerbate pre-harvest aflatoxin contamination. Tolerance and adaptation to drought stress is an important trait of agricultural crops like maize. However, maize genotypes with contrasting drought tolerances have been shown to possess both common and [...] Read more.

Drought stress decreases crop growth, yield, and can further exacerbate pre-harvest aflatoxin contamination. Tolerance and adaptation to drought stress is an important trait of agricultural crops like maize. However, maize genotypes with contrasting drought tolerances have been shown to possess both common and genotype-specific adaptations to cope with drought stress. In this research, the physiological and metabolic response patterns in the leaves of maize seedlings subjected to drought stress were investigated using six maize genotypes including: A638, B73, Grace-E5, Lo964, Lo1016, and Va35. During drought treatments, drought-sensitive maize seedlings displayed more severe symptoms such as chlorosis and wilting, exhibited significant decreases in photosynthetic parameters, and accumulated significantly more reactive oxygen species (ROS) and reactive nitrogen species (RNS) than tolerant genotypes. Sensitive genotypes also showed rapid increases in enzyme activities involved in ROS and RNS metabolism. However, the measured antioxidant enzyme activities were higher in the tolerant genotypes than in the sensitive genotypes in which increased rapidly following drought stress. The results suggest that drought stress causes differential responses to oxidative and nitrosative stress in maize genotypes with tolerant genotypes with slower reaction and less ROS and RNS production than sensitive ones. These differential patterns may be utilized as potential biological markers for use in marker assisted breeding. Full article

(This article belongs to the Special Issue Molecular Research in Plant Secondary Metabolism 2015)

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2896 KiB

Open AccessArticle

Exogenous GA₃ Application Enhances Xylem Development and Induces the Expression of Secondary Wall Biosynthesis Related Genes in Betula platyphylla

by Huiyan Guo, Yucheng Wang, Huizi Liu, Ping Hu, Yuanyuan Jia, Chunrui Zhang, Yanmin Wang, Shan Gu, Chuanping Yang and Chao Wang

Int. J. Mol. Sci. 2015, 16(9), 22960-22975; https://doi.org/10.3390/ijms160922960 - 23 Sep 2015

Cited by 42 | Viewed by 7203

Abstract

Gibberellin (GA) is a key signal molecule inducing differentiation of tracheary elements, fibers, and xylogenesis. However the molecular mechanisms underlying the effect of GA on xylem elongation and secondary wall development in tree species remain to be determined. In this study, Betula platyphylla [...] Read more.

Gibberellin (GA) is a key signal molecule inducing differentiation of tracheary elements, fibers, and xylogenesis. However the molecular mechanisms underlying the effect of GA on xylem elongation and secondary wall development in tree species remain to be determined. In this study, Betula platyphylla (birch) seeds were treated with 300 ppm GA₃ and/or 300 ppm paclobutrazol (PAC), seed germination was recorded, and transverse sections of hypocotyls were stained with toluidine blue; the two-month-old seedlings were treated with 50 μM GA₃ and/or 50 μM PAC, transverse sections of seedling stems were stained using phloroglucinol–HCl, and secondary wall biosynthesis related genes expression was analyzed by real-time quantitative PCR. Results indicated that germination percentage, energy and time of seeds, hypocotyl height and seedling fresh weight were enhanced by GA₃, and reduced by PAC; the xylem development was wider in GA₃-treated plants than in the control; the expression of NAC and MYB transcription factors, CESA, PAL, and GA oxidase was up-regulated during GA₃ treatment, suggesting their role in GA₃-induced xylem development in the birch. Our results suggest that GA₃ induces the expression of secondary wall biosynthesis related genes to trigger xylogenesis in the birch plants. Full article

(This article belongs to the Special Issue Molecular Research in Plant Secondary Metabolism 2015)

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1679 KiB

Open AccessArticle

Rapid Bioassay-Guided Isolation of Antibacterial Clerodane Type Diterpenoid from Dodonaea viscosa (L.) Jaeq.

by Muhammad Khurram, Linda A. Lawton, Christine Edwards, Marcello Iriti, Abdul Hameed, Murad A. Khan, Farman A. Khan and Shafiq Ur Rahman

Int. J. Mol. Sci. 2015, 16(9), 20290-20307; https://doi.org/10.3390/ijms160920290 - 27 Aug 2015

Cited by 10 | Viewed by 7735

Abstract

Plant extracts are complex matrices and, although crude extracts are widely in use, purified compounds are pivotal in drug discovery. This study describes the application of automated preparative-HPLC combined with a rapid off-line bacterial bioassay, using reduction of a tetrazolium salt as an [...] Read more.

Plant extracts are complex matrices and, although crude extracts are widely in use, purified compounds are pivotal in drug discovery. This study describes the application of automated preparative-HPLC combined with a rapid off-line bacterial bioassay, using reduction of a tetrazolium salt as an indicator of bacterial metabolism. This approach enabled the identification of fractions from Dodonaea viscosa that were active against Staphylococcus aureus and Escherichia coli, which, ultimately, resulted in the identification of a clerodane type diterpenoid, 6β-hydroxy-15,16-epoxy-5β, 8β, 9β, 10α-cleroda-3, 13(16), 14-trien-18-oic acid, showing bacteriostatic activity (minimum inhibitory concentration (MIC) = 64–128 µg/mL) against test bacteria. To the best of our knowledge, this is the first report on antibacterial activity of this metabolite from D. viscosa. Full article

(This article belongs to the Special Issue Molecular Research in Plant Secondary Metabolism 2015)

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De Novo Assembly and Characterization of the Transcriptome of the Chinese Medicinal Herb, Gentiana rigescens

by Xiaodong Zhang, Andrew C. Allan, Caixia Li, Yuanzhong Wang and Qiuyang Yao

Int. J. Mol. Sci. 2015, 16(5), 11550-11573; https://doi.org/10.3390/ijms160511550 - 20 May 2015

Cited by 41 | Viewed by 9543

Abstract

Gentiana rigescens is an important medicinal herb in China. The main validated medicinal component gentiopicroside is synthesized in shoots, but is mainly found in the plant’s roots. The gentiopicroside biosynthetic pathway and its regulatory control remain to be elucidated. Genome resources of gentian [...] Read more.

Gentiana rigescens is an important medicinal herb in China. The main validated medicinal component gentiopicroside is synthesized in shoots, but is mainly found in the plant’s roots. The gentiopicroside biosynthetic pathway and its regulatory control remain to be elucidated. Genome resources of gentian are limited. Next-generation sequencing (NGS) technologies can aid in supplying global gene expression profiles. In this study we present sequence and transcript abundance data for the root and leaf transcriptome of G. rigescens, obtained using the Illumina Hiseq2000. Over fifty million clean reads were obtained from leaf and root libraries. This yields 76,717 unigenes with an average length of 753 bp. Among these, 33,855 unigenes were identified as putative homologs of annotated sequences in public protein and nucleotide databases. Digital abundance analysis identified 3306 unigenes differentially enriched between leaf and root. Unigenes found in both tissues were categorized according to their putative functional categories. Of the differentially expressed genes, over 130 were annotated as related to terpenoid biosynthesis. This work is the first study of global transcriptome analyses in gentian. These sequences and putative functional data comprise a resource for future investigation of terpenoid biosynthesis in Gentianaceae species and annotation of the gentiopicroside biosynthetic pathway and its regulatory mechanisms. Full article

(This article belongs to the Special Issue Molecular Research in Plant Secondary Metabolism 2015)

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Open AccessArticle

Response of Different Genotypes of Faba Bean Plant to Drought Stress

by Manzer H. Siddiqui, Mutahhar Y. Al-Khaishany, Mohammed A. Al-Qutami, Mohamed H. Al-Whaibi, Anil Grover, Hayssam M. Ali, Mona S. Al-Wahibi and Najat A. Bukhari

Int. J. Mol. Sci. 2015, 16(5), 10214-10227; https://doi.org/10.3390/ijms160510214 - 5 May 2015

Cited by 142 | Viewed by 9644

Abstract

Drought stress is one of the major abiotic stresses that are a threat to crop production worldwide. Drought stress impairs the plants growth and yield. Therefore, the aim of the present experiment was to select the tolerant genotype/s on the basis of moprpho-physiological [...] Read more.

Drought stress is one of the major abiotic stresses that are a threat to crop production worldwide. Drought stress impairs the plants growth and yield. Therefore, the aim of the present experiment was to select the tolerant genotype/s on the basis of moprpho-physiological and biochemical characteristics of 10 Vicia faba genotypes (Zafar 1, Zafar 2, Shebam, Makamora, Espan, Giza Blanka, Giza 3, C4, C5 and G853) under drought stress. We studied the effect of different levels of drought stress i.e., (i) normal irrigation (ii) mild stress (iii) moderate stress, and (iv) severe stress on plant height (PH) plant⁻¹, fresh weight (FW) and dry weight (DW) plant⁻¹, area leaf⁻¹, leaf relative water content (RWC), proline (Pro) content, total chlorophyll (Total Chl) content, electrolyte leakage (EL), malondialdehyde (MDA), hydrogen peroxide (H₂O₂) content, and activities of catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD) of genotypes of faba bean. Drought stress reduced all growth parameters and Total Chl content of all genotypes. However, the deteriorating effect of drought stress on the growth performance of genotypes “C5” and “Zafar 1” were relatively low due to its better antioxidant enzymes activities (CAT, POD and SOD), and accumulation of Pro and Total Chl, and leaf RWC. In the study, genotype “C5” and “Zafar 1” were found to be relatively tolerant to drought stress and genotypes “G853” and “C4” were sensitive to drought stress. Full article

(This article belongs to the Special Issue Molecular Research in Plant Secondary Metabolism 2015)

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Open AccessReview

Phenolic Phytoalexins in Rice: Biological Functions and Biosynthesis

by Man-Ho Cho and Sang-Won Lee

Int. J. Mol. Sci. 2015, 16(12), 29120-29133; https://doi.org/10.3390/ijms161226152 - 7 Dec 2015

Cited by 89 | Viewed by 10117

Abstract

Phytoalexins are inducible secondary metabolites possessing antimicrobial activity against phytopathogens. Rice produces a wide array of phytoalexins in response to pathogen attacks and environmental stresses. With few exceptions, most phytoalexins identified in rice are diterpenoid compounds. Until very recently, flavonoid sakuranetin was the [...] Read more.

Phytoalexins are inducible secondary metabolites possessing antimicrobial activity against phytopathogens. Rice produces a wide array of phytoalexins in response to pathogen attacks and environmental stresses. With few exceptions, most phytoalexins identified in rice are diterpenoid compounds. Until very recently, flavonoid sakuranetin was the only known phenolic phytoalexin in rice. However, recent studies have shown that phenylamides are involved in defense against pathogen attacks in rice. Phenylamides are amine-conjugated phenolic acids that are induced by pathogen infections and abiotic stresses including ultra violet (UV) radiation in rice. Stress-induced phenylamides, such as N-trans-cinnamoyltryptamine, N-p-coumaroylserotonin and N-cinnamoyltyramine, have been reported to possess antimicrobial activities against rice bacterial and fungal pathogens, an indication of their direct inhibitory roles against invading pathogens. This finding suggests that phenylamides act as phytoalexins in rice and belong to phenolic phytoalexins along with sakuranetin. Phenylamides also have been implicated in cell wall reinforcement for disease resistance and allelopathy of rice. Synthesis of phenolic phytoalexins is stimulated by phytopathogen attacks and abiotic challenges including UV radiation. Accumulating evidence has demonstrated that biosynthetic pathways including the shikimate, phenylpropanoid and arylmonoamine pathways are coordinately activated for phenolic phytoalexin synthesis, and related genes are induced by biotic and abiotic stresses in rice. Full article

(This article belongs to the Special Issue Molecular Research in Plant Secondary Metabolism 2015)

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Carbon Fluxes between Primary Metabolism and Phenolic Pathway in Plant Tissues under Stress

by Sofia Caretto, Vito Linsalata, Giovanni Colella, Giovanni Mita and Vincenzo Lattanzio

Int. J. Mol. Sci. 2015, 16(11), 26378-26394; https://doi.org/10.3390/ijms161125967 - 4 Nov 2015

Cited by 233 | Viewed by 12469

Abstract

Higher plants synthesize an amazing diversity of phenolic secondary metabolites. Phenolics are defined secondary metabolites or natural products because, originally, they were considered not essential for plant growth and development. Plant phenolics, like other natural compounds, provide the plant with specific adaptations to [...] Read more.

Higher plants synthesize an amazing diversity of phenolic secondary metabolites. Phenolics are defined secondary metabolites or natural products because, originally, they were considered not essential for plant growth and development. Plant phenolics, like other natural compounds, provide the plant with specific adaptations to changing environmental conditions and, therefore, they are essential for plant defense mechanisms. Plant defensive traits are costly for plants due to the energy drain from growth toward defensive metabolite production. Being limited with environmental resources, plants have to decide how allocate these resources to various competing functions. This decision brings about trade-offs, i.e., promoting some functions by neglecting others as an inverse relationship. Many studies have been carried out in order to link an evaluation of plant performance (in terms of growth rate) with levels of defense-related metabolites. Available results suggest that environmental stresses and stress-induced phenolics could be linked by a transduction pathway that involves: (i) the proline redox cycle; (ii) the stimulated oxidative pentose phosphate pathway; and, in turn, (iii) the reduced growth of plant tissues. Full article

(This article belongs to the Special Issue Molecular Research in Plant Secondary Metabolism 2015)

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Constituents and Pharmacological Activities of Myrcia (Myrtaceae): A Review of an Aromatic and Medicinal Group of Plants

by Márcia Moraes Cascaes, Giselle Maria Skelding Pinheiro Guilhon, Eloisa Helena de Aguiar Andrade, Maria Das Graças Bichara Zoghbi and Lourivaldo Da Silva Santos

Int. J. Mol. Sci. 2015, 16(10), 23881-23904; https://doi.org/10.3390/ijms161023881 - 9 Oct 2015

Cited by 69 | Viewed by 12460

Abstract

Myrcia is one of the largest genera of the economically important family Myrtaceae. Some of the species are used in folk medicine, such as a group known as “pedra-hume-caá” or “pedra-ume-caá” or “insulina vegetal” (insulin plant) that it is used for the treatment [...] Read more.

Myrcia is one of the largest genera of the economically important family Myrtaceae. Some of the species are used in folk medicine, such as a group known as “pedra-hume-caá” or “pedra-ume-caá” or “insulina vegetal” (insulin plant) that it is used for the treatment of diabetes. The species are an important source of essential oils, and most of the chemical studies on Myrcia describe the chemical composition of the essential oils, in which mono- and sesquiterpenes are predominant. The non-volatile compounds isolated from Myrcia are usually flavonoids, tannins, acetophenone derivatives and triterpenes. Anti-inflammatory, antinociceptive, antioxidant, antimicrobial activities have been described to Myrcia essential oils, while hypoglycemic, anti-hemorrhagic and antioxidant activities were attributed to the extracts. Flavonoid glucosides and acetophenone derivatives showed aldose reductase and α-glucosidase inhibition, and could explain the traditional use of Myrcia species to treat diabetes. Antimicrobial and anti-inflammatory are some of the activities observed for other isolated compounds from Myrcia. Full article

(This article belongs to the Special Issue Molecular Research in Plant Secondary Metabolism 2015)

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Ethanol versus Phytochemicals in Wine: Oral Cancer Risk in a Light Drinking Perspective

by Elena M. Varoni, Giovanni Lodi and Marcello Iriti

Int. J. Mol. Sci. 2015, 16(8), 17029-17047; https://doi.org/10.3390/ijms160817029 - 27 Jul 2015

Cited by 23 | Viewed by 8322

Abstract

This narrative review aims to summarize the current controversy on the balance between ethanol and phytochemicals in wine, focusing on light drinking and oral cancer. Extensive literature search included PUBMED and EMBASE databases to identify in human studies and systematic reviews (up to [...] Read more.

This narrative review aims to summarize the current controversy on the balance between ethanol and phytochemicals in wine, focusing on light drinking and oral cancer. Extensive literature search included PUBMED and EMBASE databases to identify in human studies and systematic reviews (up to March 2015), which contributed to elucidate this issue. Independently from the type of beverage, meta-analyses considering light drinking (≤1 drinks/day or ≤12.5 g/day of ethanol) reported relative risks (RR) for oral, oro-pharyngeal, or upper aero-digestive tract cancers, ranging from 1.0 to 1.3. One meta-analysis measured the overall wine-specific RR, which corresponded to 2.1. Although little evidence exists on light wine intake, phytochemicals seem not to affect oral cancer risk, being probably present below the effective dosages and/or due to their low bioavailability. As expected, the risk of oral cancer, even in light drinking conditions, increases when associated with smoking habit and high-risk genotypes of alcohol and aldehyde dehydrogenases. Full article

(This article belongs to the Special Issue Molecular Research in Plant Secondary Metabolism 2015)

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