Complementary Transcriptome and Proteome Analyses Provide Insight into the Floral Transition in Bamboo (Dendrocalamus latiflorus Munro).

Xiaoyan Wang,Lei Zhao,Xuemei Zhang,Yujiao Wang,Dezhu Li,Zhenhua Guo,Guoqian Yang

doi:10.3390/ijms21228430

Abstract

Most woody bamboos bloom only once after long vegetative growth phases and die immediately afterwards. It is difficult, however, to determine the timing of the floral transition, as little information is available on the molecular mechanism of plant maturity in bamboos. To uncover the bamboo floral transition mechanism, its morpho-physiological characteristics, transcriptomes and large-scale quantitative proteomes were investigated in leaves which were collected at different stages during floral transition in a woody bamboo, Dendrocalamus latiflorus. We identified many flowering time-associated genes and the continued increase and decrease genes were screened as flowering biomarker genes (e.g., the MADS14 and bHLH13 genes). These different genes were assigned to specific metabolic pathways by the Kyoto Encyclopedia of Genes and Genomes (KEGG). And the photoperiod pathways depending on the circadian rhythm may play an essential role in the bamboo floral transition. In addition, a total of 721 differently expressed proteins of leaves from the vegetative-to-reproductive stages were identified. Fifty-five genes were specifically differentially expressed at both the transcriptomic and proteomic levels, including genes related to photosynthesis and nucleotide sugar, which may be involved in the floral transition. This work provides insights into bamboo flowers and the management of forest breeding.

Highlights

All organisms go through a series of distinct developmental phases during their growth [1]
Woody bamboos have unique flowering habits, but little information is available on the molecular mechanisms of bamboo flowering
We presented the application of RNA-seq to study leaves and reported a comprehensive analysis of the transcriptome, which will serve as a blueprint for the gene expression profile during floral transition

Summary

Introduction

All organisms go through a series of distinct developmental phases during their growth [1]. The transition to flowering is a critical step in these developmental phases. Most woody bamboos belong to the second category [7,8] and use a semelparity strategy, wherein they flower once and die at the end of 3–120 years (or longer) of vegetative growth phases [9]. Many bamboos have a special life history trait of monocarpic mass flowering and death, suggesting a special genetic mechanism controlling floral transition in bamboos. This collective death of bamboos results in considerable loss of forest agencies and private cultivators and has produced serious ecological crises, most strikingly for giant pandas [10]. To date, studies have been done primarily on flower development, but little has been investigated on the floral transition in bamboos

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