Search Results (7)

Salinity causes widespread crop loss and prompts plants to adapt through changes in gene expression. In this study, we aimed to investigate the function of the non-tandem CCCH zinc-finger (non-TZF) protein gene AtC3H3 in response to salt stress in Arabidopsis. AtC3H3, a gene from the non-TZF gene family known for its RNA-binding and RNase activities, was up-regulated under osmotic stress, such as high salt and drought. When overexpressed in Arabidopsis, AtC3H3 improved tolerance to salt stress, but not drought stress. The expression of well-known abscisic acid (ABA)-dependent salt stress-responsive genes, namely Responsive to Desiccation 29B (RD29B), RD22, and Responsive to ABA 18 (RAB18), and representative ABA-independent salt stress-responsive genes, namely Dehydration-Responsive Element Binding protein 2A (DREB2A) and DREB2B, was significantly higher in AtC3H3-overexpressing transgenic plants (AtC3H3 OXs) than in wild-type plants (WT) under NaCl treatment, indicating its significance in both ABA-dependent and -independent signal transduction pathways. mRNA-sequencing (mRNA-Seq) analysis using NaCl-treated WT and AtC3H3 OXs revealed no potential target mRNAs for the RNase function of AtC3H3, suggesting that the potential targets of AtC3H3 might be noncoding RNAs and not mRNAs. Through this study, we conclusively demonstrated that AtC3H3 plays a crucial role in salt stress tolerance by influencing the expression of salt stress-responsive genes. These findings offer new insights into plant stress response mechanisms and suggest potential strategies for improving crop resilience to salinity stress. Full article

Arginine-rich Tandem Zinc Finger (RR-TZF) proteins make up a plant-specific superfamily that participates in plant development, while their roles in cotton fiber development remain to be explored. In this study, we identified an RR-TZF protein-coding gene, GhTZF2, containing two CCCH domains (C-X₇-C-X₅-C-X₃-H-X₁₆-C-X₅-C-X₄-C-X₃-H) and one RR domain at the N-terminus of the two CCCH domains, by comparing the differences of chromatin H3K4me3 modifications between wild-type upland cotton (WT) and the fuzzless-lintless mutant (fl) ovules. GhTZF2 was highly expressed in ovule cells near anthesis, and multiple experiments revealed that GhTZF2 could interact directly with GhMORF8. Homozygotic GhTZF2-knockout cotton lines produced significantly shorter fibers with thinner cell walls. Additionally, comparative transcriptome analysis confirmed that many differentially expressed transcripts contain adenine- and uridine-rich (AU-rich) elements (AREs) in their 3’ untranslated regions (UTR). Together, this study indicated that GhTZF2 may regulate cotton fiber cell development through interacting with GhMORF8, or may be involved in mRNA turnover. Full article

CCCH zinc finger proteins contain one to six tandem CCCH motifs composed of three cysteine and one histidine residues and have been widely found in eukaryotes. Plant CCCH proteins control a wide range of developmental and adaptive processes through DNA–protein, RNA–protein and/or protein–protein interactions. The complex networks underlying these processes regulated by plant CCCH proteins are often involved in phytohormones as signal molecules. In this review, we described the evolution of CCCH proteins from green algae to vascular plants and summarized the functions of plant CCCH proteins that are influenced by six major hormones, including abscisic acid, gibberellic acid, brassinosteroid, jasmonate, ethylene and auxin. We further compared the regulatory mechanisms of plant and animal CCCH proteins via hormone signaling. Among them, Arabidopsis AtC3H14, 15 and human hTTP, three typical CCCH proteins, are able to integrate multiple hormones to participate in various biological processes. Full article

CCCH-type zinc finger proteins play an important role in multiple biotic and abiotic stresses. More and more reports about CCCH functions in plant development and stress responses have appeared over the past few years, focusing especially on tandem CCCH zinc finger proteins (TZFs). However, this has not been reported in Pinaceae. In this study, we identified 46 CCCH proteins, including 6 plant TZF members in Pinus massoniana, and performed bioinformatic analysis. According to RT-PCR analysis, we revealed the expression patterns of five RR-TZF genes under different abiotic stresses and hormone treatments. Meanwhile, tissue-specific expression analysis suggested that all genes were mainly expressed in needles. Additionally, RR-TZF genes showed transcriptional activation activity in yeast. The results in this study will be beneficial in improving the stress resistance of P. massoniana and facilitating further studies on the biological and molecular functions of CCCH zinc finger proteins. Full article

CCCH zinc finger proteins are a large protein family and are classified as either tandem CCCH zinc finger (TZF) or non-TZF proteins. The roles of TZF genes in several plants have been well determined, whereas the functions of many non-TZF genes in plants remain uncharacterized. Herein, we describe biological and molecular functions of AtC3H12, an Arabidopsis non-TZF protein containing three CCCH zinc finger motifs. AtC3H12 has orthologs in several plant species but has no paralog in Arabidopsis. AtC3H12-overexpressing transgenic plants (OXs) germinated slower than wild-type (WT) plants, whereas atc3h12 mutants germinated faster than WT plants. The fresh weight (FW) and primary root lengths of AtC3H12 OX seedlings were lighter and shorter than those of WT seedlings, respectively. In contrast, FW and primary root lengths of atc3h12 seedlings were heavier and longer than those of WT seedlings, respectively. AtC3H12 was localized in the nucleus and displayed transactivation activity in both yeast and Arabidopsis. We found that the 97–197 aa region of AtC3H12 is an important part for its transactivation activity. Detection of expression levels and analysis of Arabidopsis transgenic plants harboring a P_AtC3H12::GUS construct showed that AtC3H12 expression increases as the Arabidopsis seedlings develop. Taken together, our results demonstrate that AtC3H12 negatively affects seed germination and seedling development as a nuclear transcriptional activator in Arabidopsis. To our knowledge, this is the first report to show that non-TZF proteins negatively affect plant development as nuclear transcriptional activators. Full article

Despite increasing reports on the function of CCCH zinc finger proteins in plant development and stress response, the functions and molecular aspects of many non-tandem CCCH zinc finger (non-TZF) proteins remain uncharacterized. AtC3H59/ZFWD3 is an Arabidopsis non-TZF protein and belongs to the ZFWD subfamily harboring a CCCH zinc finger motif and a WD40 domain. In this study, we characterized the biological and molecular functions of AtC3H59, which is subcellularly localized in the nucleus. The seeds of AtC3H59-overexpressing transgenic plants (OXs) germinated faster than those of wild type (WT), whereas atc3h59 mutant seeds germinated slower than WT seeds. AtC3H59 OX seedlings were larger and heavier than WT seedlings, whereas atc3h59 mutant seedlings were smaller and lighter than WT seedlings. Moreover, AtC3H59 OX seedlings had longer primary root length than WT seedlings, whereas atc3h59 mutant seedlings had shorter primary root length than WT seedlings, owing to altered cell division activity in the root meristem. During seed development, AtC3H59 OXs formed larger and heavier seeds than WT. Using yeast two-hybrid screening, we isolated Desi1, a PPPDE family protein, as an interacting partner of AtC3H59. AtC3H59 and Desi1 interacted via their WD40 domain and C-terminal region, respectively, in the nucleus. Taken together, our results indicate that AtC3H59 has pleiotropic effects on seed germination, seedling development, and seed development, and interacts with Desi1 in the nucleus via its entire WD40 domain. To our knowledge, this is the first report to describe the biological functions of the ZFWD protein and Desi1 in Arabidopsis. Full article

Chinese cabbage (Brassica campestris) is an economically important leaf vegetable crop worldwide. Mounting studies have shown that cysteine-cysteine-cysteine-histidine (CCCH) zinc-finger protein genes are involved in various plant growth and development processes. However, research on the involvement of these genes in male reproductive development is still in its infancy. Here, we identified 11 male fertility-related CCCH genes in Chinese cabbage. Among them, a pair of paralogs encoding novel non-tandem CCCH zinc-finger proteins, Brassica campestris Male Fertility 30a (BcMF30a) and BcMF30c, were further characterized. They were highly expressed in pollen during microgametogenesis and continued to express in germinated pollen. Further analyses demonstrated that both BcMF30a and BcMF30c may play a dual role as transcription factors and RNA-binding proteins in plant cells. Functional analysis showed that partial bcmf30a bcmf30c pollen grains were aborted due to the degradation of pollen inclusion at the microgametogenesis phase, and the germination rate of viable pollen was also greatly reduced, indicating that BcMF30a and BcMF30c are required for both pollen development and pollen germination. This research provided insights into the function of CCCH proteins in regulating male reproductive development and laid a theoretical basis for hybrid breeding of Chinese cabbage. Full article