Regulation of OsmiR156h through Alternative Polyadenylation Improves Grain Yield in Rice.

Meng Zhao,Shixia Huang,Ruixi Han,Yuejin Wu,Qian Liu,Binmei Liu,Xiangdong Fu,Kun Wu,Yi Wang,Yafeng Ye,Shuansuo Wang,Fan Chen

doi:10.1371/journal.pone.0126154

Abstract

Substantial increases in grain yield of cereal crops are required to feed a growing human population. Here we show that a natural variant of SEMIDWARF AND HIGH-TILLERING (SDT) increases harvest index and grain productivity in rice. Gain-of-function sdt mutation has a shortened polyadenylation tail on the OsmiR156h microRNA precursor, which cause the up-regulation of OsmiR156h. The plants carrying the semidominant sdt allele exhibit reduced plant height, enhanced lodging resistance, increased tiller numbers per plant, and resulting in an increased grain yield. We also show that combining the sdt allele with the OsSPL14WFP allele can be effective in simultaneously improving tillering capacity and panicle branching, thereby leading to higher harvest index and grain yield. Most importantly, pyramiding of the sdt allele and the green revolution gene sd1 enhances grain yield by about 20% in hybrid rice breeding. Our results suggest that the manipulation of the polyadenylation status of OsmiR156 represents a novel strategy for improving the yield potential of rice over what is currently achievable.

Highlights

In the cereals, grain productivity is currently heavily dependent on the application of nitrogenous fertilizer
The sdt mutant plants displayed the reduced plant height and an increased number of tiller per plant when compared with a typical indica variety Wan3 (W3) (Fig 1a)
The gain-of-function rice sdt mutant has increased tiller number, which is the key factor accounting for the improvement of grain yield per plant, while the number of grain number per panicle and 1,000-grain weight are all reduced

Summary

Introduction

Grain productivity is currently heavily dependent on the application of nitrogenous fertilizer. Over-fertilization with nitrogen causes lodging (stem collapse prior to harvest) with a consequent loss of yield. A rice semi-dwarfing gene, sd, known as the "Green Revolution” gene [1,2], has been extensively used in rice breeding programs over the past 50 years [3]. The continuing growth of the world's population and the limited arable land resources require that grain yield capacity of rice will have to be raised yet further [4,5,6]. Grain yield loss due to lodging remains a problem in many high-yielding varieties carrying the Green Revolution sd gene [7], and the predominant use of this gene by famers and PLOS ONE | DOI:10.1371/journal.pone.0126154. Grain yield loss due to lodging remains a problem in many high-yielding varieties carrying the Green Revolution sd gene [7], and the predominant use of this gene by famers and PLOS ONE | DOI:10.1371/journal.pone.0126154 May 8, 2015

Methods

Results

Conclusion