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为研究2-(3,4-二氯苯氧基)三乙胺[2-(3,4-dichlorophenoxy)triethylamine,DCPTA]对低温胁迫下玉米(Zea mays)幼苗生长、光合特性、抗氧化系统及渗透调节物质的影响,以‘郑单958’(抗冷型)和‘丰禾1号’(冷敏感型)玉米为实验材料,盆栽培养至四叶一心时,利用人工气候箱进行低温模拟处理(14°C/5°C,昼/夜)48 h后,测定相关生理生化指标。结果表明,DCPTA处理能有效缓解低温胁迫对玉米幼苗的生长抑制作用,增加地上部鲜重、根系鲜重、叶面积和株高;DCPTA处理能够显著提高低温胁迫下玉米幼苗叶片净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)、叶绿素含量和光合系统II(PSII)最大光化学效率(Fv/Fm),降低胞间CO2浓度(Ci);同时DCPTA处理也能显著提高低温胁迫下玉米幼苗叶片超氧化物歧化酶(superoxide dismutase,SOD)、过氧化物酶(peroxidase,POD)、过氧化氢酶(catalase,CAT)与抗坏血酸过氧化物酶(ascorbate peroxidase,APX)活性;DCPTA处理还能够调节活性氧代谢,降低超氧阴离子(O2ˉ·)产生速率、H2O2含量、丙二醛(malondialdehyde,MDA)含量和相对电导率,同时幼苗叶片脯氨酸、可溶性糖及可溶性蛋白含量增加。这些结果说明DCPTA处理能够通过增强低温下植株光合电子传递效率,促进叶片光合作用,改善植株抗氧化系统运行,从而有效缓解低温胁迫对玉米幼苗叶片细胞的伤害。上述研究结果可为DCPTA应用到东北春玉米苗期抗低温生产提供理论依据。
In order to study the effect of 2- (3,4-dichlorophenoxy) triethylamine (DCPTA) on the growth, photosynthetic characteristics, antioxidant system of Zea mays seedlings under low temperature stress And osmotic adjustment substance, the experiment was conducted in the laboratory with “Zhengdan 958” (cold type) and ’Fenghe No.1’ (cold sensitive type) After treatment (14 ° C / 5 ° C, day / night) 48 h, the relevant physiological and biochemical indicators were determined. The results showed that DCPTA could effectively alleviate the growth inhibition of maize seedlings under low temperature stress and increase the fresh weight of shoots, fresh weight of roots, leaf area and plant height. DCPTA treatment could significantly increase the net photosynthetic rate (Pn) of maize seedlings under low temperature stress ), Stomatal conductance (Gs), transpiration rate (Tr), chlorophyll content and maximum photochemical efficiency (Fv / Fm) of photosystem II (PSII) and the intercellular CO2 concentration The activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) in maize seedling leaves under stress were compared. DCPTA treatment could also regulate active oxygen metabolism, decrease the production rate of O2ˉ ·, the content of H2O2, the content of malondialdehyde (MDA) and the relative conductivity of the seedlings, while proline, soluble sugar and soluble protein increase. These results indicate that DCPTA treatment can effectively alleviate the damage of leaf cells of maize seedlings under low temperature stress by enhancing the photosynthetic electron transfer efficiency, promoting leaf photosynthesis and improving the antioxidant system of plants. The above results can provide a theoretical basis for applying DCPTA to the low temperature production of spring maize seedlings in Northeast China.