LEAF TIP NECROSIS1 Plays a Pivotal Role in the Regulation of Multiple Phosphate Starvation Responses in Rice
Open Access
- 11 February 2011
- journal article
- Published by Oxford University Press (OUP) in Plant Physiology
- Vol. 156 (3), 1101-1115
- https://doi.org/10.1104/pp.110.170209
Abstract
Although phosphate (Pi) starvation signaling is well studied in Arabidopsis (Arabidopsis thaliana), it is still largely unknown in rice (Oryza sativa). In this work, a rice leaf tip necrosis1 (ltn1) mutant was identified and characterized. Map-based cloning identified LTN1 as LOC_Os05g48390, the putative ortholog of Arabidopsis PHO2, which plays important roles in Pi starvation signaling. Analysis of transgenic plants harboring a LTN1 promoter::β-glucuronidase construct revealed that LTN1 was preferentially expressed in vascular tissues. The ltn1 mutant exhibited increased Pi uptake and translocation, which led to Pi overaccumulation in shoots. In association with enhanced Pi uptake and transport, some Pi transporters were up-regulated in the ltn1 mutant in the presence of sufficient Pi. Furthermore, the elongation of primary and adventitious roots was enhanced in the ltn1 mutant under Pi starvation, suggesting that LTN1 is involved in Pi-dependent root architecture alteration. Under Pi-sufficient conditions, typical Pi starvation responses such as stimulation of phosphatase and RNase activities, lipid composition alteration, nitrogen assimilation repression, and increased metal uptake were also activated in ltn1. Moreover, analysis of OsmiR399-overexpressing plants showed that LTN1 was down-regulated by OsmiR399. Our results strongly indicate that LTN1 is a crucial Pi starvation signaling component downstream of miR399 involved in the regulation of multiple Pi starvation responses in rice.Keywords
This publication has 53 references indexed in Scilit:
- Physiological and Transcriptome Analysis of Iron and Phosphorus Interaction in Rice SeedlingsPlant Physiology, 2009
- Two rice phosphate transporters, OsPht1;2 and OsPht1;6, have different functions and kinetic properties in uptake and translocationThe Plant Journal, 2009
- OsPHR2 Is Involved in Phosphate-Starvation Signaling and Excessive Phosphate Accumulation in Shoots of PlantsPlant Physiology, 2008
- Increased expression of the MYB‐related transcription factor, PHR1, leads to enhanced phosphate uptake in Arabidopsis thalianaPlant, Cell & Environment, 2007
- Isolation and Characterization of Root-Specific Phosphate Transporter Promoters from Medicago truncatulaPlant Biology, 2006
- PHO2, MicroRNA399, and PHR1 Define a Phosphate-Signaling Pathway in PlantsPlant Physiology, 2006
- pho2, a Phosphate Overaccumulator, Is Caused by a Nonsense Mutation in a MicroRNA399 Target GenePlant Physiology, 2006
- Transcriptional regulation and functional properties of Arabidopsis Pht1;4, a high affinity transporter contributing greatly to phosphate uptake in phosphate deprived plantsPlant Molecular Biology, 2004
- Uptake and translocation of phosphate by pho2 mutant and wild-type seedlings of Arabidopsis thalianaPlanta, 1998
- A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye bindingAnalytical Biochemistry, 1976