Open AccessPhosphorus remobilization from rice flag leaves during grain filling: an RNA ‐seq study
Author(s) -
Jeong Kwanho,
Baten Abdul,
Waters Daniel L. E.,
Pantoja Omar,
Julia Cecile C.,
Wissuwa Matthias,
Heuer Sigrid,
Kretzschmar Tobias,
Rose Terry J.
Publication year - 2017
Publication title -
plant biotechnology journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.525
H-Index - 115
eISSN - 1467-7652
pISSN - 1467-7644
DOI - 10.1111/pbi.12586
Subject(s) - biology , rna , gene , transcriptome , phosphate , phosphorus , microbiology and biotechnology , starvation response , biochemistry , phosphorus deficiency , gene expression , botany , nutrient , chemistry , ecology , organic chemistry
Summary The physiology and molecular regulation of phosphorus (P) remobilization from vegetative tissues to grains during grain filling is poorly understood, despite the pivotal role it plays in the global P cycle. To test the hypothesis that a subset of genes involved in the P starvation response are involved in remobilization of P from flag leaves to developing grains, we conducted an RNA ‐seq analysis of rice flag leaves during the preremobilization phase (6 DAA ) and when the leaves were acting as a P source (15 DAA ). Several genes that respond to phosphate starvation, including three purple acid phosphatases ( Os PAP 3, Os PAP 9b and Os PAP 10a ), were significantly up‐regulated at 15 DAA , consistent with a role in remobilization of P from flag leaves during grain filling. A number of genes that have not been implicated in the phosphate starvation response, Os PAP 26, SPX ‐ MFS 1 (a putative P transporter) and SPX ‐ MFS 2 , also showed expression profiles consistent with involvement in P remobilization from senescing flag leaves. Metabolic pathway analysis using the KEGG system suggested plastid membrane lipid synthesis is a critical process during the P remobilization phase. In particular, the up‐regulation of Os PLD z2 and Os SQD 2 at 15 DAA suggested phospholipids were being degraded and replaced by other lipids to enable continued cellular function while liberating P for export to developing grains. Three genes associated with RNA degradation that have not previously been implicated in the P starvation response also showed expression profiles consistent with a role in P mobilization from senescing flag leaves.