浙江农业学报 ›› 2019, Vol. 31 ›› Issue (6): 915-921.DOI: 10.3969/j.issn.1004-1524.2019.06.08

• 园艺科学 • 上一篇    下一篇

土壤酸化对景天三七叶片光合特性及超微结构的影响

王一鸣1, 2, 龙胜举1, 陈延1, 贺忠群1, *, 赵英鹏1, 仰路希1, 严文一1   

  1. 1.四川农业大学 园艺学院,四川 成都 611130;
    2.四川省内江市农业科学院,四川 内江 641000
  • 收稿日期:2018-11-30 出版日期:2019-06-25 发布日期:2019-06-26
  • 通讯作者: 贺忠群,E-mail:hzqun328@163.com
  • 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
  • 基金资助:
    雅安市市校合作项目

Effect of soil simulated acidification on photosynthetic characteristics and ultrastructure of Sedum aizoon L. leaves

WANG Yiming1, 2, LONG Shengju1, CHEN Yan1, HE Zhongqun1, *, ZHAO Yingpeng1, YANG Luxi1, YAN Wenyi1   

  1. 1. College of Horticulture, Sichuan Agricultural University, Chengdu 611130, China;
    2. Neijiang Academy of Agricultural Sciences, Neijiang 641000, China
  • Received:2018-11-30 Online:2019-06-25 Published:2019-06-26

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(pH 3.4、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(pH 5.5)和中度(pH 4.6)酸化下植株光合及荧光参数与CK(pH 6.6)相比无显著差异,叶绿体超微结构完整;在重度(pH 3.4)酸化下,光合及荧光参数出现明显阈值响应,PnCiTrGsFoFmΦPSⅡqPFv/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。

关键词: 土壤酸化, 景天三七, 光合, 超微结构

Abstract: 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, Pn, Ci, Tr, Gs, Fo, Fm, ΦPSⅡ, qP, Fv/Fm fell rapidly, NPQ and Ls 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.

Key words: soil acidification, Sedum aizoon L., photosynthesis, ultrastructure

中图分类号: