%A WANG Dan-Dan, ZHENG Guo-Wei, LI Wei-Qi %T Changes of Membrane Stability in PotassiumStressed Plants %0 Journal Article %D 2014 %J Plant Diversity %R 10.7677/ynzwyj201413106 %P 595-602 %V 36 %N 05 %U {https://journal.kib.ac.cn/CN/abstract/article_33352.shtml} %8 2014-09-25 %X
The maintenance of membrane function is critical to the ability of plants to resist environmental stresses; specifically, the stability and appropriate fluidity of membranes are crucial to their normal function. We previously demonstrated that plants adapt to longterm potassium (K+) deficiency by accumulation of membrane lipids in leaves and maintenance of the lipid composition in roots. In this study, which involved Arabidopsis thaliana and its K+deficiencytolerant relative Crucihimalaya himalaica, we first calculated the doublebond index (DBI) as an indicator of membrane fluidity. After exposure to longterm K+deficiency stress, the DBI of the total lipids in leaves of Athaliana and Chimalaica showed no significant changes, whereas the DBI of the total lipids in the roots of these species showed slight increases. Changes in lysophospholipids (lysoPLs) levels, and digalactosyldiacylglycerol/monogalactosyldiacylglycerol (DGDG/MGDG) and phosphatidylcholine/phosphatidylethanolamine (PC/PE) ratios, all of which strongly reflect membrane stability, were also studied in K+stressed Athaliana and Chimalaica. After longterm K+ deficiency, total lysoPLs levels increased in Athaliana and Chimalaica leaves, but showed no significant changes in roots. DGDG/MGDG and PC/PE ratios were higher in Chimalaica leaves and roots than in those of Athaliana. These results indicate that Chimalaica exhibits superior membrane stability compared with Athaliana. This may explain its superior growth and tolerance under K+deficient conditions.