Diethyl Aminoethyl Hexanoate Priming Ameliorates Seed Germination via Involvement in Hormonal Changes, Osmotic Adjustment, and Dehydrins Accumulation in White Clover Under Drought Stress

Muhammad Jawad Hassan; Wan Geng; Weihang Zeng; Muhammad Ali Raza; Imran Khan; Muhammad Zafar Iqbal; Yan Peng; Yongqun Zhu; Zhou Li

doi:10.3389/fpls.2021.709187

Diethyl Aminoethyl Hexanoate Priming Ameliorates Seed Germination via Involvement in Hormonal Changes, Osmotic Adjustment, and Dehydrins Accumulation in White Clover Under Drought Stress

Front Plant Sci. 2021 Jul 29:12:709187. doi: 10.3389/fpls.2021.709187. eCollection 2021.

Authors

Muhammad Jawad Hassan¹, Wan Geng¹, Weihang Zeng¹, Muhammad Ali Raza², Imran Khan¹, Muhammad Zafar Iqbal¹, Yan Peng¹, Yongqun Zhu³, Zhou Li¹

Affiliations

¹ College of Grassland Science and Technology, Sichuan Agricultural University, Chengdu, China.
² College of Agronomy, Sichuan Agricultural University, Chengdu, China.
³ Soil and Fertilizer Research Institute, Sichuan Academy of Agricultural Sciences, Chengdu, China.

Abstract

Drought is a serious outcome of climate change reducing the productivity of forage species under arid and semi-arid conditions worldwide. Diethyl aminoethyl hexanoate (DA-6), a novel plant growth regulator, has proven to be involved in the amelioration of critical physiological functions in many agricultural crops under various abiotic stresses, but the role of the DA-6 in improving seed germination has never been investigated under drought stress. The present study was carried out to elucidate the impact of the DA-6 priming on seeds germination of white clover under drought stress. Results showed that seed priming with the DA-6 significantly mitigated the drought-induced reduction in germination percentage, germination vigor, germination index, seed vigor index, root length, shoot length, and fresh weight after 7 days of seed germination. The DA-6 significantly increased the endogenous indole-3-acetic acid, gibberellin, and cytokinin content with marked reduction in abscisic acid content in seedlings under drought stress. In addition, the DA-6 significantly accelerated starch catabolism by enhancing the activities of hydrolases contributing toward enhanced soluble sugars, proline content and ameliorated the antioxidant defense system to enhance the ability of reactive oxygen species scavenging under drought stress. Furthermore, exogenous DA-6 application significantly increased dehydrins accumulation and upregulated transcript levels of genes encoding dehydrins (SK2, Y2SK, or DHNb) during seeds germination under water deficient condition. These findings suggested that the DA-6 mediated seeds germination and drought tolerance associated with changes in endogenous phytohormones resulting in increased starch degradation, osmotic adjustment, antioxidants activity, and dehydrins accumulation during seed germination under water deficient condition.

Keywords: antioxidants; dehydrin accumulation; drought; hormonal regulation; osmotic adjustment; oxidative damage.