Down-expression of TaPIN1s Increases the Tiller Number and Grain Yield in Wheat

Fu Quan Yao,Xing Guo Li,Xian Sheng Zhang,Zhong Qing Li,Yu Ning Song,He Wang,Xin-Qi Gao,Xiao Min Bie,Xiao Hui Li

doi:10.1186/s12870-021-03217-w

Abstract

BackgroundTiller number is a factor determining panicle number and grain yield in wheat (Triticum aestivum). Auxin plays an important role in the regulation of branch production. PIN-FORMED 1 (PIN1), an auxin efflux carrier, plays a role in the regulation of tiller number in rice (Oryza sativa); however, little is known on the roles of PIN1 in wheat.ResultsNine homologs of TaPIN1 genes were identified in wheat, of which TaPIN1-6 genes showed higher expression in the stem apex and young leaf in wheat, and the TaPIN1-6a protein was localized in the plasma membrane. The down-expression of TaPIN1s increased the tiller number in TaPIN1-RNA interference (TaPIN1-RNAi) transgenic wheat plants, indicating that auxin might mediate the axillary bud production. By contrast, the spikelet number, grain number per panicle, and the 1000-grain weight were decreased in the TaPIN1-RNAi transgenic wheat plants compared with those in the wild type. In summary, a reduction of TaPIN1s expression increased the tiller number and grain yield per plant of wheat.ConclusionsPhylogenetic analysis and protein structure of nine TaPIN1 proteins were analyzed, and subcellular localization of TaPIN1-6a was located in the plasma membrane. Knock-down expression of TaPIN1 genes increased the tiller number of transgenic wheat lines. Our study suggests that TaPIN1s is required for the regulation of grain yield in wheat.

Highlights

Tiller number is a factor determining panicle number and grain yield in wheat (Triticum aestivum)
Sequence alignment revealed that wheat A, B, and D subgenomes have several homologs, including TaPIN1-6a, TaPIN1-6b1, TaPIN16b2, TaPIN1-6b3, TaPIN1-6b4, TaPIN1-6d, TaPIN1-7a, TaPIN1-7b, and TaPIN1-7d
Chromosome 6A has one copy and it was located in 543,394,469–543,397,613, chromosome 6B four copies and they were located in 593,711,770–593,714,658, chromosome 6D one copy which was located in 397,082,345– 397,084,736, chromosome 7A one copy located in 148,414,887–148,418,041, chromosome 7B one copy located in 109,702,167–109,705,332, and chromosome 7D one copy located in 146,862,702–146,865,831

Summary

Introduction

Tiller number is a factor determining panicle number and grain yield in wheat (Triticum aestivum). Auxin plays an important role in the regulation of branch production. PIN-FORMED 1 (PIN1), an auxin efflux carrier, plays a role in the regulation of tiller number in rice (Oryza sativa); little is known on the roles of PIN1 in wheat. Tiller number of wheat (Triticum aestivum) is an important agronomic trait that contributes to grain production. Environmental signals, and genetic factors are involved in the regulation of tiller number [1,2,3,4]. Shoot branching is correlated with polar auxin transport in pea (Pisum sativum) [5] and Arabidopsis [6, 7]. In Arabidopsis, eight PIN proteins are identified, which possess two conserved domains formed by transmembrane helices and a conserved central hydrophilic loop [11]

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Discussion

Conclusion