Evidence for an evolutionarily conserved interaction between cell wall biosynthesis and flowering in maize and sorghum

Wilfred Vermerris,Karen J Thompson,Lauren M Mcintyre,John D Axtell

doi:10.1186/1471-2148-2-2

Abstract

BackgroundFactors that affect flowering vary among different plant species, and in the grasses in particular the exact mechanism behind this transition is not fully understood. The brown midrib (bm) mutants of maize (Zea mays L.), which have altered cell wall composition, have different flowering dynamics compared to their wild-type counterparts. This is indicative of a link between cell wall biogenesis and flowering. In order to test whether this relationship also exists in other grasses, the flowering dynamics in sorghum (Sorghum bicolor (L.) Moench) were investigated. Sorghum is evolutionarily closely related to maize, and a set of brown midrib (bmr) mutants similar to the maize bm mutants is available, making sorghum a suitable choice for study in this context.ResultsWe compared the flowering time (time to half-bloom) of several different bmr sorghum lines and their wild-type counterparts. This revealed that the relationship between cell wall composition and flowering was conserved in sorghum. Specifically, the mutant bmr7 flowered significantly earlier than the corresponding wild-type control, whereas the mutants bmr2, bmr4, bmr6, bmr12, and bmr19 flowered later than their wild-type controls.ConclusionThe change in flowering dynamics in several of the brown midrib sorghum lines provides evidence for an evolutionarily conserved mechanism that links cell wall biosynthesis to flowering dynamics. The availability of the sorghum bmr mutants expands the germplasm available to investigate this relationship in further detail.

Highlights

Factors that affect flowering vary among different plant species, and in the grasses in particular the exact mechanism behind this transition is not fully understood
We recently reported changes in flowering dynamics in some of the brown midrib mutants of maize (Zea mays L.) [12]
There was considerable variation in the flowering time when the bmr lines were compared to their normal counterparts, and when the bmr lines were compared to each other

Summary

Introduction

Factors that affect flowering vary among different plant species, and in the grasses in particular the exact mechanism behind this transition is not fully understood. The brown midrib (bm) mutants of maize (Zea mays L.), which have altered cell wall composition, have different flowering dynamics compared to their wild-type counterparts. This is indicative of a link between cell wall biogenesis and flowering. Defining which factors affect flowering is important for a better understanding of plant growth and development and offers an opportunity to study the interactions of environmental cues, chemical signals, and gene expression. This is relevant from an agronomic perspective.

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