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6-Benzyladenine alleviates NaCl stress in watermelon (Citrullus lanatus) seedlings by improving photosynthesis and upregulating antioxidant defences.
- Source :
-
Functional Plant Biology . 2023, Vol. 50 Issue 3, p230-241. 12p. - Publication Year :
- 2023
-
Abstract
- Soil salinity is a growing problem in agriculture, plant growth regulators (PGRs) can regulate plant response to stress. The objective of this study was to evaluate the effects of exogenous 6-benzyladenine (6-BA) on photosynthetic capacity and antioxidant defences in watermelon (Citrullus lanatus L.) seedlings under NaCl stress. Two watermelon genotypes were subjected to four different treatments: (1) normal water (control); (2) 20 mg L−1 6-BA; (3) 120 mmol L−1 NaCl; and (4) 120 mmol L−1 NaCl + 20 mg L−1 6-BA. Our results showed that NaCl stress inhibited the growth of watermelon seedlings, decreased their photosynthetic capacity, promoted membrane lipid peroxidation, and lowered the activity of protective enzymes. Additionally the salt-tolerant Charleston Gray variety fared better than the salt-sensitive Zhengzi NO.017 variety under NaCl stress. Foliar spraying of 6-BA under NaCl stress significantly increased biomass accumulation, as well as photosynthetic pigment, soluble sugar, and protein content, while decreasing malondialdehyde levels, H2O2 content, and electrolyte leakage. Moreover, 6-BA enhanced photosynthetic parameters, including net photosynthetic rate, stomatal conductance, intercellular CO2 concentration, and transpiration rate; activated antioxidant enzymes, such as superoxide dismutase, catalase, and peroxidase; and improved the efficiency of the ascorbate-glutathione cycle by stimulating glutathione reductase, dehydroascorbate reductase, and monodehydroascorbate reductase, as well as ascorbic acid and glutathione content. Principal component analysis confirmed that 6-BA improved salt tolerance of the two watermelon varieties, particularly Zhengzi NO.017, albeit through two different regulatory mechanisms. In conclusion, 6-BA treatment could alleviate NaCl stress-induced damage and improve salt tolerance of watermelons by regulating photosynthesis and osmoregulation, activating the ascorbate-glutathione cycle, and promoting antioxidant defences. The antioxidant and ascorbate-glutathione cycle of two types of salt-tolerant watermelon (Citrullus lanatus L.) seedlings under NaCl stress reveal an cytokinin regulated watermelon acclimation mechanism to the NaCl stress. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 14454408
- Volume :
- 50
- Issue :
- 3
- Database :
- Academic Search Index
- Journal :
- Functional Plant Biology
- Publication Type :
- Academic Journal
- Accession number :
- 162252891
- Full Text :
- https://doi.org/10.1071/FP22047