Chinese Bulletin of Botany ›› 2016, Vol. 51 ›› Issue (2): 184-193.DOI: 10.11983/CBB15080

• EXPERIMENTAL COMMUNICATIONS • Previous Articles     Next Articles

SPL1 is Involved in the Regulation of Rhizosphere Acidification Reaction Under Low Phosphate Condition in Arabidopsis

Kaijian Lei1, 2 , Jing Ren1 , Yuanyuan Zhu1, Guoyong An1*   

  1. 1State Key Laboratory of Cotton Biology, College of Life Sciences, Henan University, Kaifeng 475004, China

    2College of Pharmacy, Henan University, Kaifeng 475004, China
  • Received:2015-05-18 Revised:2015-11-29 Online:2016-03-01 Published:2016-03-31
  • Contact: Guoyong An

Abstract:

Under low phosphate (Pi), the rhizosphere acidification of plants is a vital strategy to cope with low Pi stress. However, how plants perceive and transduce the low Pi signal and acidify the rhizosphere is not clear. A mutant, spl1, with decreased rhizosphere acidification induced by low Pi, was isolated from a T-DNA library by using the pH indicator (bromocresol purple). After 8 h incubation in low Pi medium containing bromocresol purple, the color of the rhizosphere of wild-type (WT) seedlings on the low Pi medium turned yellow, whereas that of the rhizosphere of spl1 seedlings did not change, which suggested decreased rhizosphere acidification capacity of spl1. The anthocyanin content was higher for spl1 than the WT with 20 days of low Pi treatment. The number and the length of root hairs of spl1 increased under normal conditions. Further research suggested that the Pi content of the spl1 mutant was slightly decreased in shoot but increased in root under Pi deficiency. Moreover, the expression of Pi transport-related genes in the spl1 mutant increased under Pi deficiency. Molecular genetics analysis revealed that the expression of SPL1 was induced by low Pi stress. SPL1 was mainly expressed in Arabidopsis leaves and flower tissues and the SPL1 protein was widely distributed in each part of the cell. These results indicate that SPL1 is involved in low Pi-induced rhizosphere acidification, regulation of multiple low Pi responses and Pi starvation-induced gene expression.