Low Temperature-Induced 30 (LTI30) positively regulates drought stress resistance in Arabidopsis: effect on abscisic acid sensitivity and hydrogen peroxide accumulation.

Haitao Shi,Zhulong Chan,Yongqiang Qian,Yinhua Chen

doi:10.3389/fpls.2015.00893

Abstract

As a dehydrin belonging to group II late embryogenesis abundant protein (LEA) family, Arabidopsis Low Temperature-Induced 30 (LTI30)/XERO2 has been shown to be involved in plant freezing stress resistance. However, the other roles of AtLTI30 remain unknown. In this study, we found that the expression of AtLTI30 was largely induced by drought stress and abscisic acid (ABA) treatments. Thereafter, AtLTI30 knockout mutants and overexpressing plants were isolated to investigate the possible involvement of AtLTI30 in ABA and drought stress responses. AtLTI30 knockout mutants were less sensitive to ABA-mediated seed germination, while AtLTI30 overexpressing plants were more sensitive to ABA compared with wild type (WT). Consistently, the AtLTI30 knockout mutants displayed decreased drought stress resistance, while the AtLTI30 overexpressing plants showed improved drought stress resistance compared with WT, as evidenced by a higher survival rate and lower leaf water loss than WT after drought stress. Moreover, manipulation of AtLTI30 expression positively regulated the activities of catalases (CATs) and endogenous proline content, as a result, negatively regulated drought stress-triggered hydrogen peroxide (H2O2) accumulation. All these results indicate that AtLTI30 is a positive regulator of plant drought stress resistance, partially through the modulation of ABA sensitivity, H2O2 and proline accumulation.

Highlights

Plants are exposed to various environmental conditions, plants can not change their location to avoid unfavorable circumstance (Shi et al, 2013a,b, 2014a,b)
Using proLTI30::GUS transgenic plants, we found that AtLTI30 was widely expressed in leaves, stems, flowers, primary roots and lateral roots (Figures 1A–E)
These results indicate the possible link between AtLTI30 and these stress treatments, and suggest the possible involvement of AtLTI30 in drought stress responses in Arabidopsis

Summary

Introduction

Plants are exposed to various environmental conditions, plants can not change their location to avoid unfavorable circumstance (Shi et al, 2013a,b, 2014a,b). Many secondary messengers, including abscisic acid (ABA), and hydrogen peroxide (H2O2), are involved in plant stress transduction (Seki et al, 2007; Yu et al, 2008; Fujii et al, 2009; Cutler et al, 2010; Qin et al, 2011). Eriksson et al (2011) identified three factors that regulate the lipid interaction of LTI30 in vitro, including the pH dependent His on/off switch, reversal of membrane binding by proteolytic digestion, and phosphorylation by protein kinase C

Methods

Results

Conclusion