Tissue specific transcript profiling of wheat phosphate transporter genes and its association with phosphate allocation in grains.

Vishnu Shukla,Mandeep Kaur,Jaspreet Kaur,Ajay K Pandey,Sipla Aggarwal,Shrikant Mantri,Kaushal Kumar Bhati

doi:10.1038/srep39293

Abstract

Approaches enabling efficient phosphorus utilization in crops are of great importance. In cereal crop like wheat, utilization of inorganic phosphate (Pi) is high and mature grains are the major sink for Pi utilization and storage. Research that addresses the importance of the Pi homeostasis in developing grains is limited. In an attempt to understand the Pi homeostasis in developing wheat grains, we identified twelve new phosphate transporters (PHT), these are phyologentically well distributed along with the members reported from Arabidopsis and rice. Enhanced expression of PHT1-subfamily genes was observed in roots subjected to the Pi starvation suggesting their active role in Pi homeostasis. Differential expression patterns of all the PHT genes during grain filling stages suggested their importance in the filial tissues. Additionally, high accumulation of Pi and total P in aleurone correlates well with the expression of TaPHTs and other phosphate starvation related genes. Tissue specific transcript accumulation of TaPHT1.1, TaPHT1.2, TaPHT1.4 in aleurone; TaPHT3.1 in embryo and TaPHT4.2 in the endosperm was observed. Furthermore, their transcript abundance was affected in low phytate wheat grains. Altogether, this study helps in expanding the knowledge and prioritize the candidate wheat Pi-transporters to modulate the Pi homeostasis in cereal grains.

Highlights

In grains is a demand-driven process[22]
To compare the Pi accumulation in the developing grains, Pi and total P estimation was performed in the wheat grains
Our analysis showed a slight increase in total Pi accumulation from 7 to 28 days after anthesis (DAA) of grain development (Fig. 1B)

Summary

Introduction

In grains is a demand-driven process[22]. researchers have to yet explore the mechanism involved for sensing the Pi loading in seed tissue during grain-filling. In cereals during the early stages of maturation, Pi is transported in the seeds and rapidly converted to the bound form, commonly referred as PA2,23. The high accumulation of PA in grains suggests the presence of a controlled regulatory mechanism for Pi-PA homeostasis that could be active during seed development stages[27,28]. In order to develop Pi-efficient wheat, it is important to understand the process that involves the Pi homeostasis and allocation in the developing grains of wheat. It is important to understand the step-wise regulatory mechanism for the P accumulation in the wheat seed tissues. We identified 23 wheat PHT including 12 new members that span all the four sub-families of transporters and were further characterized for their expression in filial tissues during the grain filling stages. Expression of wheat PHTs was studied in low phytate wheat, that suggested Pi-PA homeostasis in developing grains

Methods

Results

Conclusion