Abstract:To investigate the regulatory role of the HD2 deacetylase gene in Arabidopsis hypocotyls development, this study utilized wild-type plants (Col-0), HD2 mutants and overexpression plants to investigate the phenotypic characteristics of hypocotyl in normal treatment (1/2MS) and drought treatment (1/2MS+100 mmol/L mannitol) and further analyzed them based on transcriptome sequencing data. The experimental results showed that the hypocotyl lengths of the four overexpression plants was longer than that of Col-0 plants, and the elongation percentages ranging from 7.1% to 19.5%, with significant difference. And the hypocotyl lengths of the overexpression plants treated with mannitol were longer than those of Col-0 plants, with an elongation percentages ranging from 14.6% to 32.8%. The difference was more significant, and the shortening amplitude was also smaller. However, the hypocotyls length of doublegenes mutants (hd2a/hd2b and hd2a/hd2c) were significantly shorter than that of Col-0 under both conditions, and the shortening amplitude was not significantly increased after drought stress. Further transcriptome data analysis revealed that the HD2 gene affected hypocotyls development by regulating multiple photoperiod response genes and influencing plant skotomorphogenesis. Moreover, after mannitol treatment, the HD2 gene induced the production of abiotic stimulus response factors, helping the hypocotyls resist adverse environments. In summary, the HD2 gene plays an important regulatory role in Arabidopsis hypocotyl development.
