摘要
以景天三七(Sedum aizoon L.)为材料,通过浓硫酸模拟土壤酸化,研究了不同土壤酸化处理(pH3.4、4.6、5.5)对景天三七叶片光合特性及超微结构的影响。结果表明,随着土壤酸化加剧,土壤中铝离子溶出量迅速增加,叶片总叶绿素含量则逐渐降低,而细胞相对电导率和丙二醛含量逐渐增高。在轻度(pH5.5)和中度(pH4.6)酸化下植株光合及荧光参数与CK(pH6.6)相比无显著差异,叶绿体超微结构完整;在重度(pH3.4)酸化下,光合及荧光参数出现明显阈值响应,Pn、Ci、Tr、Gs、Fo、Fm、ΦPSⅡ、qP、Fv/Fm迅速降低,NPQ、Ls则显著增高,叶绿体不再沿细胞膜均匀分布,并在细胞质中扎堆聚集,基粒片层出现明显间隙,部分类囊体膜模糊不清。结果还表明,土壤酸化促进了叶片中游离脯氨酸、可溶性蛋白,以及SOD、CAT、GR和APX活性的增加,可溶性糖则呈现先增加后下降趋势。由此可见,土壤酸化导致植株叶片膜质过氧化的原因可能是促进了土壤中铝离子的析出;轻中度土壤酸化并未引起叶片光合及超微结构的变化,重度土壤酸化则会导致叶绿体结构和功能遭受破坏,光合能力降低;同时景天三七可通过诱导渗透物质的增加和抗氧化酶活性的增强以防御土壤酸化的伤害。
In this study,the effect of soil acid stress on photosynthetic characteristics and ultrastructure of Sedum aizoon L.leaves were studied by simulating soil acidification under different soil pH values (3.4,4.6,5.5).The results showed that with the intensification of soil acidification,the dissolution of aluminum ions in soil increased rapidly,while the total chlorophyll content in leaves decreased gradually and the relative cell conductivity and malondialdehyde content increased gradually.Under mild (pH 5.5) and moderate (pH 4.6) acidification,plant photosynthetic and fluorescence parameters were not significantly different from CK (pH 6.6),and chloroplast ultrastructure was intact.Under severe (pH 3.4) acidification,photosynthesis and fluorescence parameters showed obvious threshold response, P n, C i, T r, G s, F o, F m,Φ PSⅡ, qP,F v/ F m fell rapidly,NPQ and L s were significantly higher,and the chloroplast was no longer uniformly distributed along the cell membrane,and the cluster aggregated in the cytoplasm,the granum lamella appeared obvious gap,parts of the internal capsule membrane blurred.Thus,the reason of soil acidification leading to membranous peroxidation of plant leaves might be that it promoted the increase of aluminum ions in soil.Mild and moderate soil acidification did not cause changes in leaf photosynthesis and ultrastructure,while severe soil acidification would lead to destruction of chloroplast structure and function and decrease of photosynthetic capacity.At the same time,the plant can defend against the harm of soil acidification by inducing the increase of osmotic substances and the enhancement of antioxidant enzyme activity.
作者
王一鸣
龙胜举
陈延
贺忠群
赵英鹏
仰路希
严文一
WANG Yiming;LONG Shengju;CHEN Yan;HE Zhongqun;ZHAO Yingpeng;YANG Luxi;YAN Wenyi(College of Horticulture,Sichuan Agricultural University,Chengdu 611130 ,China;Neijiang Academy of Agricultural Sciences,Neijiang 641000 ,China)
出处
《浙江农业学报》
CSCD
北大核心
2019年第6期915-921,共7页
Acta Agriculturae Zhejiangensis
基金
雅安市市校合作项目
关键词
土壤酸化
景天三七
光合
超微结构
soil acidification
Sedum aizoon L.
photosynthesis
ultrastructure
作者简介
王一鸣(1992—),男,四川绵阳人,硕士,研究实习员,主要从事生物技术与遗传育种研究。E-mail:18283584261@163.com;通信作者:贺忠群,E-mail:hzqun328@163.com.
