摘要
以东营野生大豆(Glycine soja Sieb.et Zucc.ZYD 03262)和山东栽培大豆(Glycine max(L.)Merr.山宁11号)为实验材料,通过研究2种大豆植株和离体叶片对不同浓度NaCl(0,100和200 mmol/L)处理的响应,探讨2种大豆光合机构对NaCl胁迫响应的差异和机理。结果表明:NaCl处理完整植株后,2种大豆植株叶片的光合速率(Pn)、PSⅡ最大光化学效率(Fv/Fm)、PSⅡ实际光化学效率(ΦPSⅡ)和叶绿素含量都明显降低,而且生长也均受到抑制。但是,NaCl胁迫对栽培大豆各方面的抑制均显著大于野生大豆;野生大豆叶片中的Na+含量、Na+/K+值都显著低于栽培大豆,而野生大豆根中的Na+含量却明显高于栽培大豆。当用100和200 mmol/L NaCl处理2种大豆的离体叶片时,野生大豆的Fv/Fm、ΦPSⅡ、单位面积有活性反应中心的数目(RC/CS)和光化学性能指数(PI)的下降幅度却显著大于栽培大豆;叶片中的Na+含量也显著高于栽培大豆。这些结果表明,实验所用的野生大豆的光合机构并不抗盐。但是,在盐胁迫条件下,野生大豆植株却能够有效地避免过多Na+进入叶片光合组织,以维持光合机构较高的光合活性,这是野生大豆比栽培大豆更抗盐的原因之一。
Photosynthesis is the sole source of crop yield, so to understand salt resistance mechanism of photosynthetic apparatus is of paramount importance in improving salt resistance of crop. In this study, in order to explore the different salt resistance mechanisms of photosynthetic apparatus between a salt resistant wild soybean （Glycine soja Sieb. et Zucc. ZYD 03262） and a salt sensitive cultivated soybean （ Glycine max （L.） Merr. Shanning 11 ）, we investigated the responses of whole plants and detached leaves of the two soybean plants under treatments with different NaCI concentrations （0, 100, 200 mmol/L）. The results shown that the photosynthesis （Pn）, the maximum photochemical efficiency of PS 11 （Fv/Fm）, the actual photochemical efficiency of PS Ⅱ （ φPsⅡ ） , the chlorophyll content as well as plant growth were all decreased in the two soybean plants by the treatments with different concentrations of NaC1. However, the inhibition of the NaC1 on photosynthetic apparatus was more severe in the cultivated soybean than in the wild soybean. The Na^＋ contents and the ratio of Na^＋/K^＋ in leaves of the wild soybean plants were significantly lower than those of the cultivated soybean, while the Na^＋ contents in roots of the wild soybean were higher than those of the cultivated soybean, which indicates that the wild soybean can prevent more Na^＋ from getting into photosynthetic mesophyll cells. This fact may partly account for the less inhibition of the photosynthetic apparatus in the wild soybean plant under NaCl stress. To elucidate whether the photosynthetic apparatus of the wild soybean is more tolerant to Na^＋ in photosynthetic mesophyll ceils, detached fully expanded leaves of the two soybean plants were directly subjected to NaC1 solution to eliminate the difference in their selective effects of Na^＋ in their roots and stems. It is unexpectedly noticed that the Fv/Fm,the φPsⅡ , the active PSⅡ reaction centers per excited cross section （RC/CS） and the photochemical performance index （PI） decreased more significantly in detached leaves of the wild soybean than those of the cultivated soybean. The ion analysis showed that the Na^＋ contents in detached leaves of the wild soybean were higher than those of the cultivated soybean when the detached leaves were treated with 100 and 200 mmol/L NaCI. These results demonstrate that the photosynthetic apparatus in the wild soybean is not more salt tolerant than in the cultivated soybean. It is the lower Na＋ contents in photosynthetic mesophyll cells of the wild soybean plant under NaC1 stress that ensure the photosynthetic apparatus in the wild soybean to retain higher photosynthetic performance under salt stress, which is one of the mechanisms to keep higher salt resistance in the wild soybean than in the cultivated soybean.
出处
《生态学报》
CAS
CSCD
北大核心
2011年第11期3101-3109,共9页
Acta Ecologica Sinica
基金
国家重点基础研究发展计划资助项目(2009CB118505)
国家自然科学基金资助项目(30671451,30571125)
关键词
盐胁迫
野生大豆
栽培大豆
光合作用
钠离子含量
耐盐机制
salt stress
wild soybean
cultivated soybean
photosynthesis
Na^＋ contents
salt resistance
