Li Min, Yu Chunmei, Wang Yaoyi, Li Wentao, Wang Ying, Yang Yun, Liu Huihui, Li Yujuan, Tan Feng, Zhang Jian
Institute of Agricultural Science in the Regions along Yangtze River of Jiangsu, Rugao, Jiangsu Province 226541, China.
College of Life Science, Nantong University, Nantong, Jiangsu Province 226019, China.
Curr Genomics. 2014 Oct;15(5):341-8. doi: 10.2174/138920291505141106102544.
Willows are one of the most important tree species for landscaping, biofuel and raw timber. Screening salt-tolerant willow varieties is an effective approach to balance wood supply and demand. However, more salt-tolerant willow varieties are required and little is known regarding the mechanism of salt tolerance at the gene expression level. In this paper, two willow varieties were studies in terms of their differences in salt-tolerances and mechanism of salt tolerance at the level of VP1 gene expression. The results showed that Salix L0911 (L0911) had higher biomass than Salix matsudana (SM), and salt injuries were less severe in L0911 than in SM. The activities of peroxidase and superoxide dismutase, as well as the contents of soluble protein and proline, were higher in L0911 than in SM, whereas the contents of Na(+) and K(+), as well as the Na(+)/K(+) ratio, were lower in L0911 than in SM. Two VP1 genes (VP1.1 and VP1.2) cloned in L0911 and SM had similar sequences and structures. VP1.1 and VP1.2 belonged to different subgroups. Total expression levels of the VP1.1 gene in both roots and leaves of L0911 were higher than that in SM under normal conditions. Under salt stress, expression of VP1 in SM roots initially increased and then decreased, whereas the expression of VP1 in leaves of L0911 and SM, as well as in roots of L0911, decreased with increasing salt concentrations. This study increased our understanding of the salt-tolerance mechanism of willow and may facilitate the selection of salt-tolerant willow resources.
柳树是园林绿化、生物燃料和原木的最重要树种之一。筛选耐盐柳树品种是平衡木材供需的有效途径。然而，需要更多耐盐柳树品种，并且在基因表达水平上对耐盐机制知之甚少。本文研究了两个柳树品种在耐盐性差异以及VP1基因表达水平上的耐盐机制。结果表明，垂柳L0911（L0911）的生物量高于旱柳（SM），L0911的盐害比SM轻。L0911中过氧化物酶和超氧化物歧化酶的活性以及可溶性蛋白和脯氨酸的含量均高于SM，而L0911中Na(+)和K(+)的含量以及Na(+)/K(+)比值均低于SM。在L0911和SM中克隆的两个VP1基因（VP1.1和VP1.2）具有相似的序列和结构。VP1.1和VP1.2属于不同的亚组。在正常条件下，L0911根和叶中VP1.1基因的总表达水平均高于SM。在盐胁迫下，SM根中VP1的表达最初增加然后降低，而L0911和SM叶中以及L0911根中VP1的表达随盐浓度增加而降低。本研究增加了我们对柳树耐盐机制的理解，并可能有助于耐盐柳树资源的选择。
