Exogenous application of gibberellic acid and silicon to promote salinity tolerance in pea (Pisum sativum L.) through Na+ exclusion

Salinity is a worldwide problem limiting the plant growth and risking food security. This study was con-ducted to examine exogenous application of silicon (Si), gibberellic acid (GA(3)) upon the ion transport, growth, yield, and antioxidant enzymes activities of pea plant in saline conditions. Two pea varieties Meteor-FSD and Samrina Zard were pre-treated with GA(3) (10-4 M) for 12 h. Plants were allowed to grow with or without silicon in washed silica sand. Ten days old seedlings were shifted in pots with 10 kg soil. Twenty-five days old plants were exposed to 0 and 5 dS m(-1) sodium stress. Results showed that exoge-nous application of GA(3) + Si was the best treatment for increasing plant biomass and yield in the presence and absence of NaCl. Furthermore, application of Si or GA(3) enhanced chlorophyll content in the leaves, thereby increasing the net assimilation rate of pea varieties under NaCl stress by increasing the antioxidant enzyme activity. Treatment of Si alone or in combination with GA(3) significantly reduced Na+ move-ment in both pea varieties. Results showed that Si has more prominent role than GA(3) alone to build-up high plant biomass, yield, soluble protein content and reduction of Na+ transport. Samrina Zard variety showed higher yield, shoot and root dry weight as compared to Meteor-FSD variety in presence and absence of salt. It was concluded that Si can be used as a nutrient for pea under saline or non-saline conditions. Moreover, application of GA(3) has a potential role for increasing salinity tolerance, mostly in sensitive pea varieties. (C) 2022 The Author(s). Published by Elsevier B.V. on behalf of King Saud University.

Automated summary

The study investigated the effects of exogenous application of silicon (Si) and gibberellic acid (GA(3)) on the growth and yield of pea plants under saline conditions. Results showed that the application of Si or GA(3) improved plant biomass and yield, increased chlorophyll content, enhanced net assimilation rate, and reduced sodium ion transport. Si had a more prominent role than GA(3) in increasing plant biomass, yield, and protein content while reducing sodium transport. The Samrina Zard variety exhibited higher yield and shoot and root dry weight compared to the Meteor-FSD variety. Si can be used as a nutrient for pea plants in both saline and non-saline conditions, and GA(3) has the potential to increase salinity tolerance in sensitive pea varieties.