Priming seeds with hydrogen peroxide attenuates damage caused by salt stress in sorghum¹

Condicionamento de sementes com peróxido de hidrogênio atenua os danos causados pelo estresse salino em sorgo

ABSTRACT

Salinity affects physiological processes, such as photosynthesis, in various agricultural crops, such as sorghum, around the world. Thus, mitigating techniques such as priming seeds with hydrogen peroxide (H₂O₂) can increase plant tolerance to salt stress. Thus, the objective of present study was to evaluate the priming of seeds with hydrogen peroxide on gas exchange and shoot phytomass of sorghum grown under salt stress. The treatments were distributed in a randomized block design, in a 4 × 4 factorial arrangement, with four levels of electrical conductivity of irrigation water - (ECw- 0.3, 1.5, 3.5, and 5.5 dS m^-1) and four concentrations of H₂O₂ (0, 6, 12, and 18 μM L^-1), with three replications. The salinity of the water reduced gas exchange, shoot fresh and dry mass, in addition to shoot moisture content in sorghum plants. However, priming the seeds with H₂O₂ improved gas exchange and the accumulation of plant dry mass. Seed priming with H₂O₂ at dose of 8.2 µM increases the acclimatization of sorghum plants under salt stress.

Key words:
Sorghum bicolor (L.) Moench; salinity; acclimatization; photosynthesis

HIGHLIGHTS:

Soaking seeds with H₂O₂ increases salt stress acclimatization in sor-ghum plants, improving photosynthesis.

Hydrogen peroxide in alleviating salt stress in sorghum plants depends on the dose used.

Dose of 8.2 µM of H₂O₂ attenuates the negative effects of salt stress on sorghum plants.