Plant Diversity ›› 2014, Vol. 36 ›› Issue (02): 177-186.doi: 10.7677/ynzwyj201413107

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Changes in Membrane Lipids during Silique Senescence in Arabidopsis

 YU  Xiao-Mei-1、2、4, WANG  Rong-1, LI  Wei-Qi-1、3   

  1. 1 Germplasm Bank of Wild Species in Southwest China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming
    650201, China; 2 University of Chinese Academy of Sciences, Beijing 100049, China; 3 Department of Biology,
    Honghe University, Mengzi 661100, China; 4 Yuxi Zhongyan Tobacco Seed Co., Ltd, Yuxi 653100, China
  • Received:2013-05-05 Online:2014-03-25 Published:2013-07-10
  • Supported by:

    The National Natural Science Foundation of China (NSFC 30670474, 30870571, and 31070262)

Abstract:

Silique development plays an important role in the reproductive development of many species. In Arabidopsis, the seeds are contained within a silique, which is to photosynthesize in the early stages of development and the cell undergoes a programmed of senescence prior to dehiscence after silique riping. In general, degradation of membrane lipids is an essential process during plant cell senescence, however, the senescence of silique has not been reported. In the present study, the changes of molecular species in membrane lipids, the contents of membrane lipids, relative levels (%), and the doublebond index (DBI) during the senescence of siliques were examined in wildtype Arabidopsis (ecotype Wassilewskija; WS) and an Arabidopsis mutant deficient in phospholipase Dδ (PLDδKO). PLDδ is correlated closely with lipid metabolism in Arabidopsis. The present study revealed that during the senescence of siliques of Arabidopsis: (i) levels of both extraplastidic and plastidic lipids decreased significantly; (ii) the degradation of lipids did not occur at the same rate for different lipid species, the rate of decline in levels of plastidic lipids was more rapid than that of extraplastidic lipids; (iii) the DBI of total membrane lipids decreased; and (iv) in siliques of the PLDδ mutant plants, the levels and variations in the levels of membrane lipids were similar to those observed in siliques of WS. These results suggest that severe degradation of lipid molecular species occurred during Arabidopsis silique senescence. Our findings suggest that (i) the products of hydrolysis of membrane lipids may be transferred to seeds for the synthesis of triacylglycerols for lipid storage; (ii) the decline of DBI of total membrane lipids might be caused by the dramatic degradation of plastidic lipids and the relative increase of extraplastidic lipids; and (iii) PLDδ is involved in the metabolism of membrane lipids during silique senescence.

Key words: Arabidopsis, Silique senescence, Membrane lipids, Lipidomics

CLC Number: 

  • Q 945