Genetic pathways controlling inflorescence architecture and development in wheat and barley

Abstract

Modifications of inflorescence architecture have been crucial for the successful domestication of wheat and barley, which are central members of the Triticeae tribe that provide essential grains for the human diet. Investigation of the genes and alleles that underpin domestication‐related traits has provided valuable insights into the molecular regulation of inflorescence development of the Triticeae, and further investigation of modified forms of architecture are proving to be equally fruitful. The identified genes are involved in diverse biological processes, including transcriptional regulation, hormone biosynthesis and metabolism, post‐transcriptional and post‐translational regulation, which alter inflorescence architecture by modifying the development and fertility of lateral organs, called spikelets and florets. Recent advances in sequencing capabilities and the generation of mutant populations are accelerating the identification of genes that influence inflorescence development, which is important given that genetic variation for this trait promises to be a valuable resource for optimizing grain production. This review assesses recent advances in our understanding of the genes controlling inflorescence development in wheat and barley, with the aim of highlighting the importance of improvements in developmental biology for optimizing the agronomic performance of staple crop plants.

Cytokinin dehydrogenase: a genetic target for yield improvement in wheat

“…Most of the florets abort, leaving three to five grains at harvest (Feng et al , ). Unlike wheat, barley has determinate spikelets (yielding two‐rowed or six‐rowed barley) but an indeterminate spike (refer Gauley and Boden, ).…”

Plant Inflorescence Architecture: The Formation, Activity, and Fate of Axillary Meristems

“…In the grasses, a plethora of distinct inflorescence architectures are found and recent investigations in rice, maize, wheat, barley, and brachypodium are unraveling the genetic basis of each (Bommert and Whipple 2018;Chongloi et al 2019;Gauley and Boden 2019;Koppolu and Schnurbusch 2019). In the compound inflorescence of rice, flowers are borne on branches, with early arising branches forming secondary branches.…”

Wheat and barley biology: Towards new frontiers

“…Two other reviews appraise recent progress in our understanding of the genes controlling inflorescence development in wheat and barley, with the goal of highlighting the significance of improvements in developmental biology for manipulating the agronomic performance of crop plants. While Koppolu and Schnurbusch () focus in particular on two developmental genetic pathways, namely: (i) the row‐type pathway in Hordeum species: and (ii) a simplified model describing a probable mechanism of how Triticeae species form the “unbranched spike”, Gauley and Boden () discuss key domestication‐related traits of inflorescence architecture that contributed significantly to our understanding of the molecular processes that regulate inflorescence development in the Triticeae.…”