弱光胁迫下‘鄞红’葡萄光合特性及相关基因的表达

Effects of Weak Light Stress on Photosynthetic Characteristics and Relative Gene Expression of‘Yinhong' Grape

【目的】葡萄对弱光胁迫的响应及相关基因在该环境下的表达一直缺乏比较和研究,弱光下植物细胞会因逆境环境造成细胞膜系统和代谢过程的损伤,因此选择不同光照处理进行弱光胁迫的相关研究,为生产上葡萄弱光逆境的抵御提供理论依据。【方法】该文以一年生‘鄞红’葡萄为供试材料,盆栽实验,采用不同光照强度(0%、25%、40%、70%、85%)遮荫处理,研究了不同光照条件下葡萄的生长特性、光合特性、光合作用相关酶的变化;对抗逆基因PPO、PhyE进行Q-PCR表达量分析。【结果】与其它处理组相比,T1处理下(遮光率25%)各项指标良好。随着弱光胁迫程度的增强,植株生长受阻,同时叶绿素含量、净光合速率(Pn)、蒸腾速率(Tr)、Rubisco与RCA逐渐下降,而气孔导度(Gs)、胞间CO2浓度(Ci)、乙醇酸氧化酶(GO)活性逐渐上升。PPO基因表达量在胁迫环境下先升高后降低,而PhyE随遮荫程度的增加依次下调表达。重度胁迫下(70%～85%)葡萄的各项生理指标均总体呈显著下降的趋势。单层遮荫较利于‘鄞红’生长,但重度胁迫会对植株造成不可恢复的伤害,已无法通过调解自身来抵御胁迫环境。【结论】葡萄耐弱光机理较为复杂,受多种因素的影响。

【Objective】The stress response and its photosynthetic and relative gene characteristics of grape under the low light conditions remains unclearly due to the lacking of comparison and research,the plant cell membrane system and metabolic process are affected by low-light environment.Therefore,the responses of grape under different weak light stresses were studied to provide a theoretical basis for the prevention of weak light adversity.【Method】Taken‘Yinhong’grape as the tested materials with pot experiment,their growth changes,characteristics of photosynthetic enzymes under the different shading intensity levels of 0%,25%,40%,70%,85%were examined,and the gene expression of PPO and PhyE were analyzed.【Result】Compared with other treatment groups,the T1 treatment(shading rate 25%)was good.With the increase of weak light stress,the plant growth was gradually constrained,at the same time,their chlorophyll content,net photosynthetic rate(P n),transpiration rate(T r),Rubisco and RCA activity had obviously decreased,meanwhile their stomatal conductance(G s),intercellular CO 2 concentration(C i)and glycolate oxidase(GO)activity were higher than that of control.The gene expression of PPO was increased and then down-regulated in the stress environment,and the expression of PhyE was decreased with the increase of shading.The physiological indexes under higher intensity of shading(85%)were decreased significantly.Severe stress cause irreversible damage to the plant which could resist stress environment by mediating itself,and moderate shading was beneficial to plant growth.【Conclusion】The mechanism of grape-resistant under stress was complicated,which was affected by many factors.