Effects of soil drought on antioxidative metabolism of soybean pod subtending leaf during flowering and pod periods.

DU Xiang-bei; CHEN Xiao-fei; JIN Wen-jun; LEI Wei-xia; WEI Zhi; HUANG Zhi-ping; KONG Ling-cong

In order to understand the physiological mechanism of drought stress affecting premature leaf senescence of the pod subtending leaf during flowering and pod period, a pot experiment was conducted in Hefei, Anhui Province from 2021 to 2022. The effects of drought stress on the endogenous protective enzyme system and ascorbate glutathione cycle were studied based on the antioxidant metabolism system at soil water content (SWC) (75 ± 5)%, (60 ± 5)% and (45 ± 5)% on two soybean varieties (Wandou 37, drought weak sensitive variety; Wandou 38, drought sensitive variety). The results revealed that drought accelerated the senescence of pod subtending leaf, with SPAD decreasing by 8.0%-24.2% for Wandou 37 and by 12.4%-32.9% for Wandou 38. The activities of superoxide dismutase (SOD) and peroxidase (POD) and the content of ascorbic acid (ASA) were significantly increased in the pod subtending leaf, however the activities of ascorbate oxidase (APX), dehydroascorbate reductase (DHAR) and glutathione reductase (GR) were inhibited by drought stress. A large amount of H2O2 and O2- could not be completely removed, resulting in the increase of H2O2 and MDA content, and the increase of O2- production rate, which resulted in acceleration of leaf senescence. SWC (45 ± 5)% treatment was significantly higher than SWC (60 ± 5)% treatment, and the results were consistent between the two varieties. Compared with Wandou 38, Wandou 37 had higher GR and PAX activities under drought stress, increased ASA content, reduced H2O2 and O2- accumulation, and reduced the degree of membrane lipid peroxidation. Therefore it improved the resistance to drought adversity.

ASCORBATE oxidase; LIPID peroxidation (Biology); GLUTATHIONE reductase; SOIL moisture; SUPEROXIDE dismutase

Chinese Journal of Oil Crop Sciences, 2024, Vol 46, Issue 6, p1339

1007-9084

Academic Journal

10.19802/j.issn.1007-9084.2023214