Characterization and Expression Analysis of HbC3H66: Implications for Transcriptional Regulation in Rubber Biosynthesis and Abiotic Stress Responses in Hevea brasiliensis

Abstract

CCCH-type zinc-finger protein (ZnF_CCCH) family is one of the most important transcription factors (TFs) linked to various biotic and abiotic stressors and physiological and developmental processes in plants. This study aims to clone and characterise the latex gene expression patterns, evolution and characteristics of the Hevea brasiliensis ZnF_CCCH domain-containing protein 66 (HbC3H66) gene. These results showed that the open reading frame (ORF) of the HbC3H66 gene was 2,106 bp, encoding 701 aa and the calculated molecular weight of the encoded protein was 76.52 kDa. The N-terminal region of HbC3H66 contains 2 ANK repeats in, PfK_2/FBPase-2 and 2 type zinc finger motifs. Phylogenetic analysis showed that the C3H66 amino acid from Hevea and other plant C3H66 were clustered into 1 group and could be used for evolutionary analysis. Semi-quantitative RT-PCR (sqRT-PCR) revealed that the HbC3H66 mRNA was abundance in high-yielding Hevea clones (RRIT251 and RRIM600) and treatment with 2.5 % of ethephon (Eth) induced HbC3H66 mRNA expression in the latex of 15 years old Hevea trees. The HbC3H66 gene was induced by water deficit and 0.5 M NaCl in the latex of 3-month-old Hevea. In conclusion, the HbC3H66 protein may play a role in DNA-binding transcriptional regulation in NR pathways. Which would provide a theoretical basis for understanding the evolution and functions of the Hevea C3H66 gene in rubber biosynthesis. HIGHLIGHTS CCCH-type zinc-finger proteins (ZnF_CCCH) are essential transcription factors (TFs) for protein binding activity in plant growth and stress tolerance. Hevea brasiliensis zinc finger CCCH domain-containing protein 66 (HbC3H66) gene was clone and characterized. HbC3H66 contains 2 ANK repeat in, Pfk_2/FBPase-2 and 2 type zinc finger motifs. Semi-quantitative RT-PCR revealed that HbC3H66 gene was abundance in high-yielding Hevea clones (RRIT251 and RRIM600) and ethylene was induced HbC3H66 mRNA expression in the latex of Hevea The HbC3H66 gene was induced by water deficit and 0.5 M NaCl in the latex of seedling of Hevea trees. The HbC3H66 protein play a role in DNA-binding transcriptional regulation in NR pathway. GRAPHICAL ABSTRACT