HD2A and HD2C co-regulate drought stress response by modulating stomatal closure and root growth in Arabidopsis

Muhammad Sufyan Tahir; Jim Karagiannis; Lining Tian

doi:10.3389/fpls.2022.1062722

HD2A and HD2C co-regulate drought stress response by modulating stomatal closure and root growth in Arabidopsis

Front Plant Sci. 2022 Nov 23:13:1062722. doi: 10.3389/fpls.2022.1062722. eCollection 2022.

Authors

Muhammad Sufyan Tahir^{1

2}, Jim Karagiannis¹, Lining Tian^{1

2}

Affiliations

¹ Department of Biology, University of Western Ontario, London, ON, Canada.
² London Research and Development Centre, Agriculture and Agri-Food Canada, London, ON, Canada.

Abstract

Histone deacetylase 2 (HD2) is a unique family of histone deacetylases (HDACs) in plants. Despite evidence that certain HD2 family HDACs play an important role in plant growth and stress response, the coordination of HD2s in these processes remains largely unknown. We found that HD2-type, HD2A and HD2C coordinate to play a role in drought stress response in Arabidopsis. We showed that the hd2a.hd2c double mutant (Mac16) exhibit decreased drought survival and increased water loss as compared to the single mutants, hd2a and hd2c. Gene expression analysis showed that the ABI1 and ABI2 genes were upregulated and SLAC1 was downregulated which led to the modified stomatal functioning in the Mac16 as compared to the single mutants. Overexpression of HD2A and HD2C showed enhanced drought survival and decreased water loss. We also showed that the GA2ox1 and GA2ox2 genes, which are involved in the catabolism of bioactive gibberellic acids, were upregulated in the Mac16 as compared to the single mutants, which led to a decreased root growth in the Mac16. Furthermore, we showed that HD2A and HD2C can physically interact and increased genome-wide H3K9 acetylation was observed in the Mac16, compared to the single mutants. Overall, our investigation revealed that HD2A and HD2C coordinate to play a cumulative role in drought stress response and root growth in Arabidopsis.

Keywords: GA2ox2; HD2 family; HD2A; HD2C; drought stress; histone deacetylase; root growth.