AtMYB14 Regulates Cold Tolerance in Arabidopsis

Yan Chen,Juqing Kang,Hongya Gu,Zhangliang Chen,Genji Qin,Dingming Kang

doi:10.1007/s11105-012-0481-z

Yan Chen, Juqing Kang + Show 4 more

Open Access

https://doi.org/10.1007/s11105-012-0481-z

Copy DOI

Abstract

Low temperature affects plant growth and crop productivity. The CBF genes are a class of transcription factors that play important roles in cold response. Here we report that AtMYB14 participates in freezing tolerance in Arabidopsis by affecting expression of CBF genes. The AtMYB14 gene was down-regulated by cold treatment. AtMYB14 encodes a nuclear protein that functions as an R2R3-MYB transcription activator. Knock-down of AtMYB14 by artificial microRNA increased the tolerance to freezing stress. Both the CBF genes and the downstream genes were induced to a much higher level in AtMYB14 knock-down plants than in wild type under cold treatment. Our results suggest that AtMYB14 plays an important role in the plant response to cold stress.

Highlights

Low temperature is one of the most stressful environmental factors affecting plant growth and development
The results showed that one transcription factor, AtMYB14, was significantly downregulated by cold stress, whereas the relative expression level of AtMYB14 at normal temperature (22 °C) at different times showed no changes in expression, indicating that changes in expression of AtMYB14 were not due to circadian rhythm
ProAtMYB14::GUS transgenic plants were treated at 0 °C for 24 h; GUS staining showed that the GUS activity decreased significantly under cold treatment in the seedling stage (Fig. 1b)

Summary

Introduction

Low temperature is one of the most stressful environmental factors affecting plant growth and development. Overexpression of ICE1 causes elevated expression of CBF3, CBF2 and downstream genes in cold stress, and enhances freezing tolerance to low temperature. A MYB transcription factor AtMYB15 regulates CBF genes negatively. AtMYB15 lossof-function mutants increase tolerance to cold stress through elevating the expression of CBF genes. AtMYB15, interacting with ICE1, binds to MYB recognition sequences in the promoter regions of CBF genes and down-regulates CBF genes (Agarwal et al 2006). MYB transcription factors have been found to regulate many physiological and biochemical processes, such as secondary metabolism, plant development and stress response (Kranz et al 1998; Stracke et al 2001; Chen et al 2006a). The expression of CBF genes and cold-response downstream genes were increased to a much higher degree in AtMYB14 knock-down plants than in wild type under cold treatment. Our results indicate that AtMYB14 is an important element in the signaling pathway of cold tolerance

Materials and Methods

Results

Discussion