Regulation Effects Of DCPTA On Salt Resistance Of Maize Seedlings

The Saline-alkali land area was about 667000 ha in the western of Heilongjiang Province, the Saline-alkali soil restricts the further enhance of the level of food production in Heilongjiang province. Enhancing the salt tolerance of crops played a significant role in development and utilization of this part of land resources. Chemical control technology was one of the methods to enhance the stress resistance of crops. DCPTA was one of tertiary amines active substances and played an important role in improving crop yields, quality and stress resistance, the research of DCPTA was very popular in recent years.The objective of this study was to investigate the regulation effects of DCPTA on salt tolerance of maize seedlings. Hydroponic experiments were performed with ‘Xianyu 335’(salt-tolerant) and ‘Fenghe No.1’(salt-sensitive) to investigate the effects of DCPTA(15 mg·L-1) on growth, relative water content, cell membrane stability, photosynthetic characteristics, chlorophyll fluorescence, osmotic adjustment, antioxidant enzymes activity, and endogenous hormones of maize seeding under salt stress(150 mmol·L-1), to reveal the mechanism of maize salt tolerance enhanced by DCPTA and provide theoretical and practical basis for the application of DCPTA in maize production under stress. The results showed that:DCPTA application led to a marked increase in shoot dry weight, shoot fresh weight, root dry weight, root fresh weight, root length, root surface, root volume of maize seedling, promoted the growth and development of root and alleviated the growth inhibition of seedlings under the condition of salt stress.The exogenous DCPTA may play an important role in stabilizing leaves plasma membrane structure and function. The malondialdehyde(MDA) content and relative conductivity of ‘Xianyu 335’ and ‘Fenghe No.1’ under DCPTA pretreatment were decreased by 26.4% and 26.0%, 31.3% and 33.5%, respectively.DCPTA treatment under salt stress led to an increase in Pn, Gs, Tr, Fv/Fm, ΦPSII and q P, a decrease in Ci and NPQ of maize leaves, effectively alleviated the non-stomatal limitation on photosynthesis of seedlings, improved the photochemical activity of PSII reaction centers, and improved the photosynthetic ability of seedlings under salt stress.DCPTA enhanced the osmotic adjustment ability of maize seedling leaves by increasing soluble sugar and soluble protein and decreasing proline content, maintained the water balance of maize seedling leaves and significantly improved the relative water content of seedling leaves. DCPTA could significantly improve SOD, POD, CAT activity of seedling leaves under salt stress, this was beneficial to clear excess ROS induced by salt stress, ease membrane lipid peroxidation, alleviate the oxidative damage of salt stress on seedlings.DCPTA significantly decreased ABA content, significantly increased IAA, GA, ZR content, and IAA/ABA, GA3/ABA, ZR/ABA of seedling leaves under salt stress, enhanced salt tolerance of seedlings by adjusting the balance between endogenous hormones.The alleviating effect of DCPTA on damage by salt stress of ‘Fenghe No.1’ were greater than ‘Xianyu 335’, DCPTA has a better effect on salt-sensitive maize variety.DCPTA could significantly alleviate the damage of salt stress on seedlings, and DCPTA could be used as a chemical regulation agent on improving the salt tolerance of maize seedlings.