叶面喷施新型渗透剂TMAO提高百脉根耐旱性

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中图分类号：S541.6 文献标识码：A 文章编号：1007-0435（2026）01-0323-08

Abstract：The objective of this study was to determine whether the novel osmolyte trimethylamine N-oxide （TMAO）enhances drought tolerance of Lotus japonicus and to preliminarily reveal the coresponding physiological mechanisms. L. japonicus ecotype‘Miyakojima’MG-2O was used in the study.Five concentrations of TMAO （0.1mmol⋅L-1 ， 0.5mmol⋅L-1 ， 1mmol⋅L-1 ， 5mmol⋅L-1 ，and 10mmol⋅L-1 ）and were sprayed on MG2O leaves daily for 7d ，plants were then immediately subjected to drought treatment for 28d ， followed by rewatering for 7d . Based on plant phenotype， 5mmol⋅L-1 TMAO was selected as the best concentration to improve the drought tolerance of L . japonicus. To further investigate the underlying physiological mechanism， 5mmol⋅L-1 TMAO was sprayed on leaves for 7d followed by drought tolerance evaluation.After 28 days of drought，plant height，leaf relative water content （LRWC），chlorophyllcontent （Chl），and photo chemical efficiency （Fv/Fm ）were significantly lower in both drought-stressed plants sprayed with （DW） or TMAO （D-T） compared to well-watered controls sprayed with ddH2O （W-W） or TMAO（W-T）. However，these parameters were significantly higher in the D-T group than in the D-W group. Concurrently， leafrelative electrolyte leakage（EL）and superoxide anion（ O2- ）accumulation in leaves were significantly higherin the D-W and D-T groups compared to the W-Wand W-T groups，but significantly lower in the D-T group than in the D-W group.Folowing 7 days of rewatering，chlorophyll content remained significantly higher in the D-T group compared to the D-W group，while no significant differences were observed in the other measured parameters between these two groups. These results indicate that foliar application of TMAO can aleviate drought-induced damage inL.japonicus，providing an efectiveapproach for improving cultivation under drought conditions.

Key words：Lotus japonicus;TMAO;Drought stress;Physiological index

干旱作为威胁全球生态平衡最大的自然灾害之一，具有发生频率高、持续时间长及影响范围广等特点，对农业生产、生态环境和社会经济发展产生深远的影响[1]。（剩余13578字）