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以番茄品种‘合作903’为试材,采用基质栽培的方式,研究外源喷施24-表油菜素内酯(EBR)对亚低温弱光复合胁迫下番茄幼苗生长、碳同化和抗氧化代谢的影响。结果表明,亚低温弱光胁迫显著降低番茄幼苗株高和干鲜重,外源EBR缓解复合胁迫诱导的生长抑制。胁迫条件下施用EBR处理后,番茄叶片Rubisco最大羧化速率(V_(cmax))、最大电子传递速率(J_(max))、磷酸丙糖利用率(TPU)和羧化效率(CE)分别显著提高了113.57%、90.71%、38.92%和287.50%,CO_2补偿点(CCP)降低了16.38%。EBR显著增加了复合胁迫下番茄叶片蔗糖磷酸合成酶(SPS)和蔗糖合酶(SS)的活性,而降低酸性转化酶(AI)活性,导致可溶性糖含量、果糖含量和蔗糖含量下降。外源EBR显著提高了亚低温弱光胁迫下番茄叶片抗氧化酶的活性,与单纯复合胁迫相比,超氧化物岐化酶(SOD)、过氧化物酶(POD)、抗坏血酸氧化酶(APX)和过氧化氢酶(CAT)的活性分别增加了31.78%、65.69%、59.99%和187.66%,并降低了超氧阴离子(O_2~(ˉ·))产生速率和丙二醛(MDA)含量。说明EBR通过调节碳同化和抗氧化代谢,缓解了亚低温弱光复合胁迫对番茄生长的抑制,进而增强胁迫条件下番茄植株的抗性。
Using the cultivar ’903’ as test material, the effects of exogenous spraying 24-epibrassinolide (EBR) on the growth, carbon assimilation and anti-oxidative metabolism of tomato seedlings under low-low temperature and weak light combined stress Impact. The results showed that low and moderate low light stress significantly decreased plant height and fresh weight of tomato seedlings, and exogenous EBR relieved the growth inhibition induced by compound stress. Rubisco maximal carboxylation rate (V cmax), maximum electron transfer rate (J max), TPU and carboxylation efficiency (CE) of tomato leaves under stress were significantly higher than those of control Increased by 113.57%, 90.71%, 38.92% and 287.50%, while the CO_2 compensation point (CCP) decreased by 16.38%. EBR significantly increased the activity of sucrose phosphate synthase (SPS) and sucrose synthase (SS), and decreased the activity of acid invertase (AI), resulting in the decrease of soluble sugar content, fructose content and sucrose content under combined stress. Exogenous EBR significantly increased the antioxidant enzyme activity of tomato leaves under mild and moderate hypothermia, compared with the simple combination stress, the activities of superoxide dismutase (SOD), peroxidase (POD), ascorbate oxidase (APX) ) And catalase (CAT) increased by 31.78%, 65.69%, 59.99% and 187.66%, respectively, and decreased the production rate of superoxide anion (O_2ˉˉˉ) and the content of malondialdehyde (MDA) . EBR alleviates the inhibition of tomato growth by mild and moderate combined stresses of low and moderate temperature by regulating carbon assimilation and antioxidant metabolism, and then enhances the resistance of tomato plants under stress.