ABSTRACT
Phytohormones play a pivotal role in regulating plant growth and responding to salt stress, aiding in signal perception and defense system mediation. With this, the objective of the present study was to assess the impact of phytohormone application in mitigating the harmful effects of salt stress on radish. Three levels of NaCl (0, 50, and 100 mM) and five phytohormones (jasmonic acid, salicylic acid, cytokinin, gibberellin, and polyamine) plus a control treatment (deionized water) were studied. The application of phytohormones such as jasmonic acid and cytokinin improved photosynthetic efficiency, and diameter, length, and total soluble solids content of tuber. Under salt stress conditions, plants showed adaptations in gas exchange, varying their rates of photosynthesis and transpiration. Furthermore, an effective balance between carbon assimilation and water loss was observed in some plants. The application of phytohormones counteracted salt stress, safeguarding chlorophyll, sustaining gas exchange, and promoting plant growth of radish. Consequently, use of phytohormones represents an alternative for radish cultivation under salt stress.
Key words:
Raphanus sativus; chlorophyll indices; gas exchange; growth
HIGHLIGHTS:
Phytohormones mitigate the reduction of chlorophyll in salt-stressed radish, sustaining photo-synthesis.
Stomatal regulation by phytohormones enhances radish photosynthesis under salt stress.
Phytohormones influence radish tuber, promoting growth and improving shape.
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Same uppercase letters do not differ for phytohormones, and same lowercase letters do not differ for salt stress according to the Tukey’s test (p ≤ 0.05). Crl- control, JA- jasmonic acid, SA- salicylic acid, CK- cytokinin, GA- gibberellic acid, PA- polyamine; Vertical bars represent standard deviation of mean (n= 4)
Vertical bars with the same uppercase letter do not differ for phytohormones, and vertical bars with the same lowercase letter do not differ for salt stress according to the Tukey’s test (p ≤ 0.05). Crl- control, JA- jasmonic acid, SA- salicylic acid, CK- cytokinin, GA- gibberellic acid, PA- polyamine; Vertical bars represent standard deviation of mean (n= 4)
Vertical bars with the same uppercase letter do not differ for phytohormones, and vertical bars with the same lowercase letter do not differ for salt stress according to Tukey’s test (p ≤ 0.05). Crl- control, JA- jasmonic acid, SA- salicylic acid, CK- cytokinin, GA- gibberellic acid, PA- polyamine; Vertical bars represent standard deviation of mean (n= 4)
