title: Potassium Retention under Salt Stress Is Associated with Natural Variation in Salinity Tolerance among Arabidopsis Accessions.
abstract: Plants are exposed to various environmental stresses during their life cycle such as salt, drought and cold. Natural variation mediated plant growth adaptation has been employed as an effective approach in response to the diverse environmental cues such as salt stress. However, the molecular mechanism underlying this process is not well understood. In the present study, a collection of 82 Arabidopsis thaliana accessions (ecotypes) was screened with a view to identify variation for salinity tolerance. Seven accessions showed a higher level of tolerance than Col-0. The young seedlings of the tolerant accessions demonstrated a higher K(+) content and a lower Na(+)/K(+) ratio when exposed to salinity stress, but its Na(+) content was the same as that of Col-0. The K(+) transporter genes AtHAK5, AtCHX17 and AtKUP1 were up-regulated significantly in almost all the tolerant accessions, even in the absence of salinity stress. There was little genetic variation or positive transcriptional variation between the selections and Col-0 with respect to Na+-related transporter genes, as AtSOS genes, AtNHX1 and AtHKT1;1. In addition, under salinity stress, these selections accumulated higher compatible solutes and lower reactive oxygen species than did Col-0. Taken together, our results showed that natural variation in salinity tolerance of Arabidopsis seems to have been achieved by the strong capacity of K(+) retention.
authors.affiliation: The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, College of Life Sciences, Shandong University, 27 Shanda South Road, Jinan, 250100, Shandong, China.
authors.forename: Yanling
authors.initials: Y
authors.lastname: Sun
authors.affiliation: The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, College of Life Sciences, Shandong University, 27 Shanda South Road, Jinan, 250100, Shandong, China.
authors.forename: Xiangpei
authors.initials: X
authors.lastname: Kong
authors.affiliation: The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, College of Life Sciences, Shandong University, 27 Shanda South Road, Jinan, 250100, Shandong, China.
authors.forename: Cuiling
authors.initials: C
authors.lastname: Li
authors.affiliation: The Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, 100093, Beijing, China.
authors.forename: Yongxiu
authors.initials: Y
authors.lastname: Liu
authors.affiliation: The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, College of Life Sciences, Shandong University, 27 Shanda South Road, Jinan, 250100, Shandong, China.
authors.forename: Zhaojun
authors.initials: Z
authors.lastname: Ding
mesh_terms: D000222:Adaptation, Physiological; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics; D014644:Genetic Variation; D010084:Oxidation-Reduction; D011188:Potassium / Q000378:metabolism*; D027961:Potassium-Hydrogen Antiporters / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D013014:SOS Response, Genetics; D054712:Salinity; D013312:Stress, Physiological
chemical_list: D029681:Arabidopsis Proteins; D027961:Potassium-Hydrogen Antiporters; D012333:RNA, Messenger; C501258:potassium transporter, Arabidopsis; D011188:Potassium