RNA function and phosphorus use by photosynthetic organisms.

John A Raven

doi:10.3389/fpls.2013.00536

Abstract

Phosphorus (P) in RNA accounts for half or more of the total non-storage P in oxygenic photolithotrophs grown in either P-replete or P-limiting growth conditions. Since many natural environments are P-limited for photosynthetic primary productivity, and peak phosphorus fertilizer production is inevitable, the paper analyses what economies in P allocation to RNA could, in principle, increase P-use efficiency of growth (rate of dry matter production per unit organism P). The possibilities of decreasing P allocation to RNA without decreasing growth rate include (1) more widespread down-regulation of RNA production in P-limited organisms, (2) optimal allocation of P to RNA, both spatially among cell compartments and organs, and temporally depending on the stage of growth, and (3) a constant rate of protein synthesis through the diel cycle. Acting on these suggestions would, however, be technically demanding.

Highlights

RNA is an essential component of all living organisms, and the phosphorus (P) it contains cannot be substituted by any other element
The core role of RNA is in protein synthesis, involving mRNA, rRNA, and tRNA, but it has derived functions in regulation of gene expression
The paper first deals with the general background of the molecular biology, biochemistry, physiology and biogeochemistry, including optimal allocation of P within the organism in the context of the Growth Rate Hypothesis (Sterner and Elser, 2002). It considers the various ways of expressing the RNA content of photosynthetic organisms, and the upper limit of the in vivo peptide elongation rate per ribosome

Summary

INTRODUCTION

RNA is an essential component of all living organisms, and the phosphorus (P) it contains cannot be substituted by any other element. The paper first deals with the general background of the molecular biology, biochemistry, physiology and biogeochemistry, including optimal allocation of P within the organism in the context of the Growth Rate Hypothesis (Sterner and Elser, 2002). It considers the various ways of expressing the RNA content of photosynthetic organisms, and the upper limit of the in vivo peptide elongation rate per ribosome. The paper concludes with consideration of how plant P-use efficiency could be increased by maximizing protein synthesis rate per unit RNA at all times and in all parts of the organism

BACKGROUND

Findings

CONCLUSIONS AND REQUIREMENTS FOR