AtCRY2 Negatively Regulates the Functions of AtANN2 and AtANN3 in Drought Tolerance by Affecting Their Subcellular Localization and Transmembrane Ca2+ Flow

Ting Liu; Leyan Du; Qiushi Li; Jingda Kang; Qi Guo; Shilin Wang

doi:10.3389/fpls.2021.754567

AtCRY2 Negatively Regulates the Functions of AtANN2 and AtANN3 in Drought Tolerance by Affecting Their Subcellular Localization and Transmembrane Ca²⁺ Flow

Front Plant Sci. 2021 Nov 23:12:754567. doi: 10.3389/fpls.2021.754567. eCollection 2021.

Authors

Ting Liu^{1

2}, Leyan Du², Qiushi Li^{1

2}, Jingda Kang², Qi Guo^{2

3}, Shilin Wang^{2

4}

Affiliations

¹ College of Teacher Education, Hebei Normal University, Shijiazhuang, China.
² College of Life Sciences, Hebei Normal University, Shijiazhuang, China.
³ Root Biology Center, College of Natural Resources and Environment, South China Agricultural University, Guangzhou, China.
⁴ College of Agriculture, South China Agricultural University, Guangzhou, China.

Abstract

Annexins are a multifunctional class of calcium-binding proteins in plants, and their physiological functions and regulation in response to drought stress remain to be elucidated. Here, we found that AtANN2 and AtANN3 conferred to drought tolerance under short-day and long-day conditions, respectively. Under their functional photoperiod, AtANN2 and AtANN3 gene expression was enhanced in the mannitol-treated roots, and their encoded proteins were rapidly targeted to the plasma membrane, and mediated significant Ca²⁺ flows across the plasma membrane. Cryptochromes as photoreceptors can not only sense the photoperiod and regulate ion channels on the plasma membrane to influence ion flow but also induce downstream physiological responses. AtCRY2 repressed the functions of AtANN2 and AtANN3 by affecting their plasma membrane localization and inhibited AtANN2- and AtANN3-dependent transmembrane Ca²⁺ flow in response to drought stress. Taken together, these results uncover a mechanism linking Annexins-AtCRY2 to transmembrane Ca²⁺ flow and resulting in enhanced drought tolerance in Arabidopsis.

Keywords: annexin; calcium; cryptochrome; drought tolerance; photoperiod.