β-Amino-butyric acid protects Arabidopsis against low potassium stress

• Published in: Acta physiologiae plantarum 2008-05, Vol.30 (3), p.309-314
• Main Authors: Cao, Shuqing, Jiang, Li, Yuan, Huaibo, Jian, Hongyong, Ren, Guang, Bian, Xiaohui, Zou, Jizhi, Chen, Zhengyi
• Format: Article
• Language: English
• Subjects: Agriculture; Biomedical and Life Sciences; Life Sciences; Original Paper; Plant Anatomy/Development; Plant Biochemistry; Plant Genetics and Genomics; Plant Pathology; Plant Physiology
• ISSN: 0137-5881; 1861-1664
• DOI: 10.1007/s11738-007-0122-6

Potassium (K + ) is an essential element for plant growth and development. Under low-K + stress, Arabidopsis ( Arabidopsis thaliana ) plants show K + -deficient symptoms, typically leaf chlorosis and subsequent inhibition of plant growth and development. The non-protein amino acid β-amino-butyric acid (BABA) has been shown to have roles in protecting Arabidopsis against various pathogens as well as drought, high salinity, and cadmium stresses; However, little is known about the role of BABA in protecting Arabidopsis against low-K + stress. Here, we showed that BABA protects Arabidopsis against low-K + stress by increasing K + uptake under low-K + condition. Leaf chlorosis of plants subjected to low-K + stress was abolished by BABA pretreatment, as indicated by a lower reduction in chlorophyll content in BABA-treated plants than water-treated plants. Low-K + stress-induced decreases in both lateral root length and the numbers of lateral roots were improved by BABA pretreatment. In addition, under low-K + stress, a significantly higher K + concentration was detected in BABA-pretreated plants than in water-treated plants, and the transcript levels of AtHAK5 and LKS1 genes involved in K + uptake in BABA-treated plants were higher than those of water-treated plants. Taken together, our results suggest that BABA plays a role in enhancing low-K + stress tolerance by increasing K + uptake, at least in part, via modulation of AtHAK5 and LKS1 under low-K + condition.