玉米黄质对低温弱光下辣椒光合能力和叶黄素循环的影响

Effects of zeaxanthin on photosynthesis capacity and xanthophyll cycle of pepper under low temperature and weak light

为进一步探究玉米黄质对辣椒低温弱光耐受性的影响,以低温敏感性辣椒‘航椒2号’为试验材料,通过叶面喷施玉米黄质,研究其对低温弱光(15℃/5℃,100μmol·m^(-2)·s-1)胁迫下辣椒光合作用关键酶活性、叶绿素荧光参数、内源激素含量、叶黄素循环及相关基因表达量的影响,探究玉米黄质缓解辣椒幼苗低温弱光胁迫的生理机制。结果表明:喷施玉米黄质显著提高辣椒幼苗低温弱光下的光合能力,PSⅡ最大光化学量子产量(F_(v)/F_(m))、实际光化学量子产量Y(Ⅱ)分别显著提高5.90%和54.33%,处理后168 h茉莉酸(JA)和生长素(IAA)含量分别显著增加16.70%和62.30%;辣椒幼苗花药黄质、紫黄质、叶黄素和玉米黄质含量分别增加了1.06、0.48、0.19倍和1.57倍,同时在胁迫处理24、48、168 h时CaZEP基因表达量分别显著增加了3.44、1.64倍和5.50倍,而CaVDE基因表达量与对照相比未达到显著性差异。综上所述,喷施玉米黄质可能通过增强低温弱光下辣椒幼苗光合能力、调控激素代谢以及促进辣椒幼苗启动叶黄素循环来提高辣椒幼苗对低温弱光胁迫的耐受性。

To further explore the 0x09effects of zeaxanthin on weak temperature and weak light tolerance of hot pepper,the effects of zeaxanthin on the activities of key photosynthetic enzymes,chlorophyll fluorescence parameters,endogenous hormone content,xanthophyll cycle and related gene expression in pepper‘Hangjiao 2’under low temperature and weak light stress(15℃/5℃,100μmol·m^(-2)·s-1)were studied,and the physiological mechanism of zeaxanthin in alleviating low temperature and weak light stress of pepper seedlings were explored.The results showed that spraying zeaxanthin significantly increased the photosynthetic capacity of pepper seedlings under low temperature and weak light,and the maximum photochemical quantum yield(F_(v)/F_(m))and actual photochemical quantum yield Y(Ⅱ)were significantly increased by 5.90%and 54.33%,respectively.The contents of jasmonic acid(JA)and auxin(IAA)increased significantly by 16.70%and 62.30%.The contents of antheraxanthin,violaxanthin,xanthophyll and zeaxanthin in pepper seedlings increased by 1.06,0.48,0.19 times and 1.57 times,respectively.At the same time,the expression of CaZEP gene increased significantly by 3.44,1.64 times and 5.50 times at 24,48,168 h,but there was no significant difference in CaVDE gene expression.To sum up,spraying zeaxanthin might enhance the tolerance of pepper seedlings to low temperature and low light stress by enhancing the photosynthetic capacity of pepper seedlings,regulating hormone metabolism,and promoting the initiation of xanthophyll cycle in pepper seedlings.