摘要
该实验以2年生黄连幼苗为材料,在100mmol·L-1的NaCl模拟盐胁迫条件下,经不同浓度的外源5-氨基乙酰丙酸(ALA)处理后,测定黄连幼苗光合色素含量、叶绿素荧光参数及气体交换参数等光合生理指标的变化,探寻提高黄连幼苗在盐胁迫条件下抗性能力的途径。结果显示:(1)NaCl胁迫下黄连幼苗的光合生理受到显著抑制,在经过不同浓度的ALA处理后,显著提高了叶绿素a、叶绿素b、总叶绿素和类胡萝卜素等光合色素的含量。(2)盐胁迫下,黄连植株的的净光合速率(Pn)、气孔导度(Gs)及叶片蒸腾速率(Tr)均发生下降,并且随着胁迫时间和胁迫浓度的增加下降幅度逐渐增大,胞间CO2浓度(Ci)则呈上升趋势,说明盐胁迫下黄连净光合速率降低的主要影响因素是非气孔因素。(3)用ALA处理后,黄连的Pn、Gs及Tr均有不同程度的提高,Ci也有不同程度的降低,并且不同的浓度梯度存在着显著的效果差异。(4)ALA处理还提高了最大荧光(Fm,1.234)、最大光化学效率(Fv/Fm,0.849)、PSⅡ有效光化学效率(Fv′/Fm′,0.685)、PSⅡ实际光化学效率(ΦPSⅡ,0.545)和光化学淬灭系数(qP,0.872)的水平,有效降低了初始荧光(F0,0.211)和非光化学淬灭系数(NPQ,0.251)的水平。研究表明,外源ALA通过提高黄连幼苗叶片的光合色素含量,减少过剩激发能的耗散,提高光合电子传递效率,有效缓解了盐胁迫对黄连叶片PSⅡ的伤害,提高了植株的抗盐能力。
In order to get the method of alleviate salinity damage to Coptis chinensis Franch. under salt stress,we used exogenous 5-aminolevulinic acid（ALA） in the experiment. Several physiological indexes like the contents of photosynthetic pigment, chlorophyll fluorescence and photosynthesis parameters, of C. chinensis were measured treated by ALA under salt stress（NaC1 with the concentration of 100 mmol· L-1 ）. The study results indicated that： （1）The exogenous ALA obviously increased the contents of chloro- phyll a,chlorophyll b, total chlorophyll, and carotenoids. （2）The levels of Pn, Gs, and T, of C. chinensis seedlings were all decreased with the increased concentrations and treatment days under salinity stress, and the value of C increased with the opposite tendency. These results indicate that the main influencing factor to the decreasing net photosynthetic rate of C. chinensis is non-stomatal factors. （3）After treated with dif- ferent concentrations of exogenous ALA, the Pn, Gs, and Tr were all increased with different degrees, and the level of C~ was decreased. （4）ALA applied in the experiment also increased maximum fluorescence（Fm 1. 234）, photochemical efficiency of photosystem II （Fv/Fm 0. 849） photochemical efficiency （ , Fv Fro , 0. 685）, PS II actual photochemical efficiency （ΦPSⅡ, 0. 545）, photochemical quench coefficient （qp , 0. 872）, decreased the levels of minimal fluorescence （F0,0. 211） and non-photochemical quenching coefficient （NPQ,O. 251）. As can be seen,ALA with the appropriate concentration of 50 mg· g-1 could significantly alleviate the damage of salt stress to C. chinensis, reduce excess excitation dissipation and improve photo- chemical electron transport efficiency and efficiently protect from PS II damage. ALA obviously promoted the salt resistance of C. chinensis under salt stress.
出处
《西北植物学报》
CAS
CSCD
北大核心
2014年第12期2515-2524,共10页
Acta Botanica Boreali-Occidentalia Sinica
基金
国家自然科学基金(31300222
81302744)
江苏省自然科学基金(BK20130214)
江苏省高校自然科学研究项目(13KJB180025)
徐州医学院优秀人才科研启动基金
关键词
黄连
5-氨基乙酰丙酸
盐胁迫
叶绿素荧光
光合特性
Coptis chinensis Franch.
5-aminolevulinic acid
salt stress
chlorophyll fluorescence
photosynthesis characteristics
