Search Results (7)

Hypocotyl length is closely related to quality in seedlings and is an important component of plant height vital for plant-type breeding in cucumber. However, the underlying molecular mechanisms of hypocotyl elongation are poorly understood. In this study, the endogenous hormone content of indole acetic acid (IAA) and gibberellin (GA₃) showed an increase in the long hypocotyl Csphyb (phytochrome B) mutant AM274M compared with its wild-type AM274W. An RNA-sequencing analysis identified 1130 differentially expressed genes (DEGs), of which 476 and 654 were up- and downregulated in the mutant AM274M, respectively. A KEGG enrichment analysis exhibited that these DEGs were mainly enriched in the plant hormone signal transduction pathway. The expression levels of the pivotal genes CsGA20ox-2, in the gibberellin biosynthesis pathway, and CsYUCCA8, in the auxin biosynthesis pathway, were notably elevated in the hypocotyl of the mutant AM274M, in contrast to the wild-type AM274W. Additionally, GUS staining and a dual-luciferase reporter assay corroborated that the phytochrome-interacting factors CsPIF3/4 can bind to the E(G)-box motifs present in the promoters of the CsGA20ox-2 and CsYUCCA8 genes, thereby modulating their expression and subsequently influencing hypocotyl elongation. Consequently, this research offers profound insights into the regulation of hypocotyl elongation by auxin and gibberellin in response to light signals and establishes a crucial theoretical groundwork for cultivating robust cucumber seedlings in agricultural practice. Full article

Poor selectivity is one of the main bottlenecks restricting the development of metal oxide semiconductor (MOS) sensors. In this paper, using hydrogen cyanide (HCN) as the target gas, CeMnOx as the catalytic layer material and Pt@SnO₂ as the gas-sensitive layer material, we have proposed a scheme to improve the selectivity of a catalytic layer/gas-sensitive layer-laminated MOS sensor under dynamic temperature modulation. We tested HCN and 12 kinds of battlefield environment simulation gases, and the results showed that the CeMnOx/Pt@SnO₂ sensor, under the condition of temperature dynamic modulation (a constant temperature of 400 °C for the gas-sensitive layer and a variable temperature of room temperature to 400 °C for the catalytic layer; the heating and cooling rates were 200 °C/s, the highest temperature was maintained for 2 s, and the lowest temperature was maintained for 2 s), distinct characteristic peaks appeared on the G-T curves of the resistance response to HCN only. The quantification of the characteristic peaks was performed by peak heights, and the peak height of 5 mg/m³ HCN was obtained up to 0.104, while the peak heights of the other gases at the same concentration were up to 0.034. The peak height of HCN was significantly higher than that of other gases, which verified the high selectivity of the sensor for HCN. Meanwhile, the sensor also showed good sensitivity, response/recovery time, stability and anti-interference for HCN under the above temperature dynamic modulation. This work provides an important reference for the selectivity improvement of MOS sensors for HCN. Full article

High labor costs and labor shortages are limiting factors affecting the tea industry in Anhui Province. Thus, exploiting the full mechanization of shoot harvesting is an urgent task in the tea industry. Tea quality is greatly influenced by the integrity rate of tea leaves; therefore, it is important to choose tea cultivars suitable for machine picking. In this study, seven tea cultivars were used to investigate the relationship between internode length and blade angle with respect to newly formed tea shoots and machine harvesting in field experiments (Xuanchen City, Kuiling village) conducted throughout the year (in the autumn of 2021, in the early spring of 2022, and in the summer of 2022). Our results showed that the internode length (L2 or L4) had a significant and positive correlation with the integrity rate of tea buds and leaves in seven tea cultivars over three seasons. However, no significant correlation was found between the blade angle and the integrity rate of tea buds and leaves. In addition, a strong and positive correlation was found between the levels of GA₁ (R2 > 0.7), GA₃ (R2 > 0.85), and IAA (R2 > 0.6) regarding the internodes and internode lengths of the seven tea cultivars. Moreover, the relative expression levels of CsGA20ox, CsGA3ox1, and CsGA3ox2 in Echa1 (the longer internode) were significantly higher compared with those in Zhenong113 (the shorter internode). Overall, our results show that the internode length is an important factor for the machine harvesting of tea leaves and that the level of GA3 is strongly associated with internode length. Full article

Clade A protein phosphatase 2Cs (PP2CAs) negatively regulate abscisic acid (ABA) signaling. Here, we investigated the functions of OsPP2CAs and their crosstalk with ABA and gibberellic acid (GA) signaling pathways in rice (Oryza sativa). Among the nine OsPP2CAs, OsPP2C08 had the highest amino acid sequence similarity with OsPP2C51, which positively regulates GA signaling in rice seed germination. However, OsPP2C08 was expressed in different tissues (internodes, sheaths, and flowers) compared to OsPP2C51, which was specifically expressed in seeds, and showed much stronger induction under abiotic stress than OsPP2C51. Transgenic rice lines overexpressing OsPP2C08 (OsPP2C08-OX) had a typical ABA-insensitive phenotype in a post-germination assay, indicating that OsPP2C08, as with other OsPP2CAs, negatively regulates ABA signaling. Furthermore, OsPP2C08-OX lines had longer stems than wild-type (WT) plants due to longer internodes, especially between the second and third nodes. Internode cells were also longer in OsPP2C08-OX lines than in the WT. As GA positively regulates plant growth, these results suggest that OsPP2C08 might positively regulate GA biosynthesis. Indeed, the expression levels of GA biosynthetic genes including gibberellin 20-oxidase (OsGA20ox4) and Ent-kaurenoic acid oxidase (OsKAO) were increased in OsPP2C08-OX lines, and we observed that GIBBERELLIN 2-OXIDASE 4 (OsGA2ox4), encoding an oxidase that catalyzes the 2-beta-hydroxylation of several biologically active GAs, was repressed in the OsPP2C08-OX lines based on a transcriptome deep sequencing and RT-qPCR analysis. Furthermore, we compared the accumulation of SLENDER RICE 1 (SLR1), a DELLA protein involved in GA signaling, in OsPP2C08-OX and WT plants, and observed lower levels of SLR1 in the OsPP2C08-OX lines than in the WT. Taken together, our results reveal that OsPP2C08 negatively regulates ABA signaling and positively regulates GA signaling in rice. Our study provides valuable insight into the molecular mechanisms underlying the crosstalk between GA and ABA signaling in rice. Full article

To improve the performance of amorphous InGaZnO_x (a-IGZO) thin film transistors (TFTs), in this thesis, Cs⁺ ions adsorbed IGZO (Cs-IGZO) films were prepared through a solution immersion method at low temperature. Under the modification of surface structure and oxygen vacancies concentrations of a-IGZO film, with the effective introduction of Cs⁺ ions into the surface of a-IGZO films, the transfer properties and stability of a-IGZO TFTs are greatly improved. Different parameters of Cs⁺ ion concentrations were investigated in our work. When the Cs⁺ ions concentration reached 2% mol/L, the optimized performance Cs-IGZO TFT was obtained, showing the carrier mobility of 18.7 cm² V⁻¹ s⁻¹, the OFF current of 0.8 × 10⁻¹⁰ A, and the threshold voltage of 0.2 V, accompanied by the threshold voltage shifts of 1.3 V under positive bias stress for 5000 s. Full article

Cucumber (Cucumis sativus L.) is an important vegetable crop worldwide and gibberellins (GAs) play important roles in the regulation of cucumber developmental and growth processes. GA oxidases (GAoxs), which are encoded by different gene subfamilies, are particularly important in regulating bioactive GA levels by catalyzing the later steps in the biosynthetic pathway. Although GAoxs are critical enzymes in GA synthesis pathway, little is known about GAox genes in cucumber, in particular about their evolutionary relationships, expression profiles and biological function. In this study, we identified 17 GAox genes in cucumber genome and classified them into five subfamilies based on a phylogenetic tree, gene structures, and conserved motifs. Synteny analysis indicated that the tandem duplication or segmental duplication events played a minor role in the expansion of cucumber GA2ox, GA3ox and GA7ox gene families. Comparative syntenic analysis combined with phylogenetic analysis provided deep insight into the phylogenetic relationships of CsGAox genes and suggested that protein homology CsGAox are closer to AtGAox than OsGAox. In addition, candidate transcription factors BBR/BPC (BARLEY B RECOMBINANT/BASIC PENTACYSTEINE) and GRAS (GIBBERELLIC ACID-INSENSITIVE, REPRESSOR of GAI, and SCARECROW) which may directly bind promoters of CsGAox genes were predicted. Expression profiles derived from transcriptome data indicated that some CsGAox genes, especially CsGA20ox1, are highly expressed in seedling roots and were down-regulated under GA₃ treatment. Ectopic over-expression of CsGA20ox1 in Arabidopsis significantly increased primary root length and lateral root number. Taken together, comprehensive analysis of CsGAoxs would provide a basis for understanding the evolution and function of the CsGAox family. Full article

Gibberellins (GAs), a class of diterpenoid phytohormones, play a key role in regulating diverse processes throughout the life cycle of plants. Bioactive GA levels are rapidly regulated by Gibberellin-dioxygenases (GAox), which are involved in the biosynthesis and deactivation of gibberellin. In this manuscript, a comprehensive genome-wide analysis was carried out to find all GAox in Camellia sinensis. For the first time in a tea plant, 14 CsGAox genes, containing two domains, DIOX_N (PF14226) and 2OG-FeII_Oxy, were identified (PF03171). These genes all belong to 2-oxoglutarate-dependent dioxygenases (2-ODD), including four CsGA20ox (EC: 1.14.11.12), three CsGA3ox (EC: 1.14.11.15), and seven CsGA2ox (EC: 1.14.11.13). According to the phylogenetic classification as in Arabidopsis, the CsGAox genes spanned five subgroups. Each CsGAox shows tissue-specific expression patterns, although these vary greatly. Some candidate genes, which may play an important role in response to external abiotic stresses, have been identified with regards to patterns, such as CsGA20ox2, CsGA3ox2, CsGA3ox3, CsGA2ox1, CsGA2ox2, and CsGA2ox4. The bioactive GA levels may be closely related to the GA20ox, GA3ox and GA2ox genes. In addition, the candidate genes could be used as marker genes for abiotic stress resistance breeding in tea plants. Full article