Regulation of soybean drought response by mepiquat chloride pretreatment

Xiyue Wang; Xinyu Zhou; Zhipeng Qu; Chao Yan; Chunmei Ma; Jun Liu; Shoukun Dong

doi:10.3389/fpls.2023.1149114

Regulation of soybean drought response by mepiquat chloride pretreatment

Front Plant Sci. 2023 May 8:14:1149114. doi: 10.3389/fpls.2023.1149114. eCollection 2023.

Authors

Xiyue Wang¹, Xinyu Zhou¹, Zhipeng Qu¹, Chao Yan¹, Chunmei Ma¹, Jun Liu², Shoukun Dong¹

Affiliations

¹ College of Agriculture, Northeast Agricultural University, Harbin, China.
² Lab of Functional Genomics and Bioinformatics, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China.

Abstract

Introduction: Soybean is the world's most important cultivated crop, and drought can affect their growth and, eventually, yields. Foliar application of mepiquat chloride (MC) can potentially alleviate the damage caused by drought stress in plants; however, the mechanism of MC regulation of soybean drought response has not been studied.

Methods: This study investigated the mechanism of soybean drought response regulation by mepiquat chloride in two varieties of soybean, sensitive Heinong 65 (HN65) and drought-tolerant Heinong44 (HN44), under three treatment scenarios, normal, drought stress, and drought stress + MC conditions.

Results and discussion: MC promoted dry matter accumulation under drought stress, reduced plant height, decreased antioxidant enzyme activity, and significantly decreased malondialdehyde content. The light capture processes, photosystems I and II, were inhibited; however, accumulation and upregulation of several amino acids and flavonoids by MC was observed. Multi-omics joint analysis indicated 2-oxocarboxylic acid metabolism and isoflavone biosynthetic pathways to be the core pathways by which MC regulated soybean drought response. Candidate genes such as LOC100816177, SOMT-2, LOC100784120, LOC100797504, LOC100794610, and LOC100819853 were identified to be crucial for the drought resistance of soybeans. Finally, a model was constructed to systematically describe the regulatory mechanism of MC application in soybean under drought stress. This study fills the research gap of MC in the field of soybean resistance.

Keywords: drought stress; growth characteristic; mepiquat chloride; molecular mechanism; physiology; soybean.

Grants and funding

This work was supported by the National Key R&D Program of China, (Grant No. 2018YFD1000903), and the Natural Science Foundation of Heilongjiang Province of China (Grant No. LH2021C023).