Comprehensive Genome-Wide Exploration of C2H2 Zinc Finger Family in Grapevine (Vitis vinifera L.): Insights into the Roles in the Pollen Development Regulation.

Some C2H2 zinc-finger proteins (ZFP) transcription factors are involved in the development of pollen in plants. In grapevine (Vitis vinifera L.), it has been suggested that abnormalities in pollen development lead to the phenomenon called parthenocarpy that occurs in some varieties of this cultivar. At present, a network involving several transcription factors types has been revealed and key roles have been assigned to members of the C2H2 zinc-finger proteins (ZFP) family in model plants. However, particularities of the regulatory mechanisms controlling pollen formation in grapevine remain unknown. In order to gain insight into the participation of ZFPs in grapevine gametophyte development, we performed a genome-wide identification and characterization of genes encoding ZFP (VviZFP family). A total of 98 genes were identified and renamed based on the gene distribution into grapevine genome. The analysis performed indicate significant changes throughout VviZFP genes evolution explained by high heterogeneity in sequence, length, number of ZF and presence of another conserved domains. Moreover, segmental duplication participated in the gene family expansion in grapevine. The VviZFPs were classified based on domain and phylogenetic analysis into three sets and different groups. Heat-map demonstrated differential and tissue-specific expression patterns of these genes and k-means clustering allowed to identify a group of putative orthologs to some ZFPs related to pollen development. In transgenic plants carrying the promVviZFP13::GUS and promVviZFP68::GUS constructs, GUS signals were detectable in the anther and mature pollen grains. Expression profiling of selected VviZFP genes showed differential expression pattern during flower development and provides a basis for deepening in the understanding of VviZFPs role on grapevine reproductive development.

JcZFP8, a C2H2 zinc finger protein gene from Jatropha curcas, influences plant development in transgenic tobacco

Background: Jatropha curcas L., as an important strategic biofuel resource with considerable economic potential, has attracted worldwide attention. However, J. curcas has yet to be domesticated. Plant height, an important agronomic trait of J. curcas, has not been sufficiently improved, and the genetic regulation of this trait in J. curcas is not fully understood. Zinc finger proteins (ZFPs), a class of transcription factors, have previously been shown to play critical roles in regulating multiple aspects of plant growth and development and may accordingly be implicated in the genetic regulation of plant height in J. curcas. Results: In this study, we cloned JcZFP8, a C2H2 ZFP gene in J. curcas. We found that the JcZFP8 protein was localized in the nucleus and contained a conserved QALGGH motif in its C2H2 structure. Furthermore, ectopic expression of JcZFP8 under the control of the 35S promoter in transgenic tobacco resulted in dwarf plants with malformed leaves. However, when JcZFP8 was knocked out, the transgenic tobacco did not show the dwarf phenotype. After treatment with the gibberellic acid (GA) biosynthesis inhibitor paclobutrazol (PAC), the dwarf phenotype was more severe than plants that did not receive the PAC treatment, whereas application of exogenous gibberellin3 (GA3) reduced the dwarf phenotype in transgenic plants. Conclusions: The results of this study indicate that JcZFP8 may play a role in J. curcas plant phenotype through GA-related pathways. Our findings may help us to understand the genetic regulation of plant development in J. curcas and to accelerate breeding progress through engineering of the GA metabolic pathway in this plant. How to cite: Shi X,Wu Y, Dai T, et al. JcZFP8, a C2H2 zinc-finger protein gene from Jatropha curcas, influences plant development in transgenic tobacco.