1、中文 2635 字 ,1634单词，英文字符 8440 出处： Plant Growth Regulation 32: 99103, 2000. Improving salt tolerance of cotton seedlings with 5-aminolevulinic acid K.Watanabe1, T. Tanaka1, Y. Hotta1, H. Kuramochi2 & Y. Takeuchi2 ABSTRACT Of 12 different plant growth regulators (PGRs) tested, 5-aminolevulinic acid (ALA
2、) was found to improve the salt tolerance of cotton seedlings. Cotton seedlings treated with ALA could grow in soil containing levels as high as 1.5% (wt/wt) NaCl. The analyses of mineral compositions of plant parts revealed that the Na+ concentrations in the roots of the plants treated with ALA wer
3、e suppressed to low concentrations. From these results, it can be presumed that the presence of ALA may cause a reduction of Na+ uptake. Abbreviations: PGRs plant growth regulators; ALA 5-aminolevulinic acid hydrochloride; GA 3 gibberellin; BA benzyladenine; IAA indoleacetic acid; ABA abscisic acid
4、Key words: 5-aminolevulinic acid, cotton, Na+ uptake, plant growth regulators, salt-stress tolerance 1. Introduction The salinization of soil has become an increasingly important topic. Because few crop plants can be grown successfully in saline soil where crop productivity is markedly low, saline l
5、and is rarely used as farmland. At the same time, the total area of arable land is gradu- ally decreasing due to the progressive salinization of soil 16. The improvement of crop productivity in regions subjected to salt damage is a more serious and pressing challenge than ever for promoting desert g
6、reening and preventing the desertification of the earth. A number of studies are currently underway inwhich researchers are trying to cultivate plants in saline soil. For example, the possibility of imparting salt-stress tolerance to food crops such as rice and tobacco using genetic engineering and similar molecular-biological methods is under investigation 12, 15. More research is needed before the knowl- edge gained can be used in practice. Plant growth regulators (PG
