Arabidopsis PHL2 and PHR1 Act Redundantly as the Key Components of the Central Regulatory System Controlling Transcriptional Responses to Phosphate Starvation. Issue 1 (19th November 2015)

• Record Type: Journal Article
• Authors: Sun, Lichao; Song, Li; Zhang, Ye; Zheng, Zai; Liu, Dong
• Is Part Of: Plant physiology. Volume 170:Issue 1(2016)
• Page Start: 499
• Page End: 514
• Publication Date: 2015-11-19
• Subjects: Plant physiology -- Periodicals; Botany -- Periodicals; Periodicals; Electronic journals; 571.2
• DOI: 10.1104/pp.15.01336
• Languages: English
• ISSNs: 0032-0889

Abstract

Abstract : Two transcription factors act redundantly to regulate the transcriptional responses to phosphate starvation at genomic level. Abstract: When confronted with inorganic phosphate (Pi ) starvation, plants activate an array of adaptive responses to sustain their growth. These responses, in a large extent, are controlled at the transcriptional level. Arabidopsis ( Arabidopsis thaliana ) PHOSPHATE RESPONSE1 (PHR1) and its close homolog PHR1-like 1 (PHL1) belong to a 15-member family of MYB-CC transcription factors and are regarded as the key components of the central regulatory system controlling plant transcriptional responses to Pi starvation. The knockout of PHR1 and PHL1, however, causes only a partial loss of the transcription of Pi starvation-induced genes, suggesting the existence of other key components in this regulatory system. In this work, we used the transcription of a Pi starvation-induced acid phosphatase, AtPAP10, to study the molecular mechanism underlying plant transcriptional responses to Pi starvation. We first identified a DNA sequence on the AtPAP10 promoter that is critical for the transcription of AtPAP10 . We then demonstrated that PHL2 and PHL3, two other members of the MYB-CC family, specifically bind to this DNA sequence and activate the transcription of AtPAP10 . Unlike PHR1 and PHL1, the transcription and protein accumulation of PHL2 and PHL3 are upregulated by Pi starvation. RNA-sequencing analyses indicated that the transcription of most Pi starvation-induced genes is impaired in the phl2 mutant, indicating that PHL2 is also a key component of the central regulatory system. Finally, we showed that PHL2, and perhaps also PHL3, acts redundantly with PHR1 to regulate plant transcriptional response to Pi starvation.