ENDOPHYTIC INFECTION PROGRAMS THE ASCORBATEGLUTATHIONE CYCLE IN RICE (ORYZA SATIVA L.) UNDER Na2CO3 STRESS

Abstract

Soil salinization and alkalization have been identified as one of the principal causes of impaired productivity of rice plants worldwide. Endophytes reprogram plant metabolism and elicit beneficial effects on rice growth under salt-alkali stress. This work investigates the potential effects of endophytic infection on the key players in specifically the metabolism, ascorbate-glutathione cycle, in rice seedlings (Oryza sativa L.) under Na2CO3 stress. Compared to uninfected controls, endophytic infection significantly increased the activities of glutathione reductase and ascorbate peroxidase, the contents of total ascorbic acid, reduced ascorbic acid, total glutathione and reduced glutathione, and the ratios of reduced ascorbic acid/dehydroascorbic acid and reduced glutathione/oxidized glutathione, but decreased the dehydroascorbic acid and oxidized glutathione contents in rice seedlings under Na2CO3 stress. In addition, H2O2 and proline contents in rice seedlings were significantly decreased by endophytic infection. Taken together, endophytic infection holds great promise to improve the resistance to Na2CO3 stress for rice plants and the underlying mechanisms involves modulation of the metabolic intensity of ascorbate-glutathione cycle.