Determination Of Betaines And Proline In Plant Tissues Under Salt-stress

Salinization of soil, a whole world resource and ecological problem, becomes one of limiting factors to the whole world's agricultural production. With the growing of population and the limited field, it is important to develop and utilize the salinized soil. Studying the mechanism of plants resistant to salt-stress is the foundation of biological method, which is an economical and potential approach to improve the salt soil.The aim of this study is to assay the variations in amount of betaine and proline in the 5 kinds of plants under salt-stress, establish relationship between these variations and plant's salt tolerance and construct a model based on evaluating crop germplasm, breeding cultivars and cloning genes for salt tolerance.The 5 kinds of plants showed different salt tolerant capacity when they were stressed by salt. According to salt-tolerant capacity in plants, the order from higher to lower was as following: Suaeda heteroptera Kitag; beet; wild barley; SW12, a salt resistant variety in wheat; Tiaoshan, a comment variety in barley; wheat variety Ningchun No. 4; Chinese Spring, a salt sensitive variety in wheat; Zhongye No.1, salt resistant variety in soybean and Jackson, salt sensitive variety in soybean.hi this study, betaines and proline in the 5 kinds of plants under salt stress were simultaneously separated by cation exchange HPLC and identified and quantified by ESI-MS. Based on HPLC-ESI-MS, glycine betaine (GB), 0 - alanine betaine(AB), trigonelline (Trg), proline betaine (PB), 4-hydroxyproline betaine(HPB) and proline were determined rapidly, selectively and sensitively.The amount of betaine in the 5 kinds of plants was closely related to salt tolerance in plants and the different varieties in same crop. The ANOVA result of betaine amount in the 5 kinds of plants showed that there was distinct difference among them (alpha = 0.01). The most amount of betaine in the leaf of 5 plants under salt-stress and under control are 11477.4μg/gFW and 32.7μg/gFW respectively. The most amount of betaine in the root of 5 plants under salt-stress and under control are 3237.9μg/gFW and 0.3μg/gFW respectively. Further analyses (T=2.59) displayed that order of betanie amount in plants was Suaeda heteroptera Kitag, wild barley, beet, salt resistant wheat variety SW12, wheat variety Ningchun No.4, barley variety Tiaoshan, salt sensitive wheat variety Chinese Spring, salt resistant soybean variety Zhongye No. 1 and soybean sensitive variety Jackson. The result was accorded with plant's salt tolerant capacity. It suggested that amount of betaine in plants may be a important compound that acts as compatible solute or osmoprotectant when plants was salt stressed tolerance.This relationship was not found between the amount of proline and salt tolerance in plant. The ANOVA results of proline amount showed that there were different between the leaf and roots and were not consistent with the salt tolerant capability in the 5 kinds of plants. So, the amount of proline in plant may not be a compatible solute, it only might be a harmful index while plants were salt stressed.