A sugarcane R2R3-MYB transcription factor gene is alternatively spliced during drought stress

Abstract

MYB transcription factors of the R2R3-MYB family have been shown to play important roles in many plant processes. A sugarcane R2R3-MYB gene (ScMYB2) and its two alternative forms of transcript (ScMYB2S1 and ScMYB2S2) were identified in this study. The deduced protein of ScMYB2S1 is a typical plant R2R3-MYB protein, while ScMYB2S2 encodes a truncated protein. Real-time qPCR analysis revealed that ScMYB2S1 is suppressed under PEG-simulated drought stress in sugarcane, while ScMYB2S2 is induced at later treatment stage. A senescence symptom was observed when ScMYB2S1 was injected into tobacco leaves mediated by Agrobacterium, but no symptom for ScMYB2S2. Further investigation showed that the expression levels of 4 senescence-associated genes, NtPR-1a, NtNYC1, NtCAT3 and NtABRE, were markedly induced in tobacco leaves after ScMYB2S1-injection, while they were not sensitive to ScMYB2S2-injection. Moreover, MDA and proline were also investigated after injection. Similarly, MDA and proline levels were induced by ABA and ScMYB2S1, while inhibited by ScMYB2S2. We propose that ScMYB2, by alternatively splicing two transcripts (ScMYB2S1 and ScMYB2S2), is involved in an ABA-mediated leaf senescence signaling pathway and play positive role in respond to drought-induced senescence in sugarcane. The results of this study provide information for further research in sugarcane stress processes.

Differential expression between drought-tolerant and drought-sensitive sugarcane under mild and moderate water stress as revealed by a comparative analysis of leaf transcriptome

“…Rice overexpressing OsbZIP52 showed down-regulation of stress-related genes and significantly increased sensitivity to drought (Liu, Wu & Wang, 2012). Sugarcane R2R3-MYB was reported to be involved in an ABA-mediated leaf senescence signaling pathway (Guo et al, 2017) and expression of one of its isoforms could reduce biomass accumulation (Fávero Peixoto-Junior et al, 2018). In contrast, NAC100, which was up-regulated in UT12, was reported to cause early-senescence and positively regulated chlorophyll-degrading genes (Oda-Yamamizo et al, 2016).…”

Overexpression of the Wild Soybean R2R3-MYB Transcription Factor GsMYB15 Enhances Resistance to Salt Stress and Helicoverpa Armigera in Transgenic Arabidopsis

“…Lots of studies have suggested that plant R2R3-MYB TFs play crucial roles in both abiotic and biotic stresses. Most studies are founding their important functions on environment stresses and plant disease [50,51,52,53,54]. However, very few studies explore their functions in plant-insect interactions, especially in soybean plants.…”

Transcription Factors in Plant Stress Responses: Challenges and Potential for Sugarcane Improvement

“…Recently, a study reported that the overexpression of ScMYBAS1-3 was associated with drought resistance and biomass accumulation in rice transgenic lines [114]. Another observation revealed that a sugarcane ScMYB2 was participated in an ABA-mediated leaf senescence signaling pathway and acted as a positive regulator in respond to PEG-mediated drought stress [115]. OsMYB3 from rice was observed to enhance tolerance against cold, while OsMYB2 was observed to enhance tolerance against dehydration, cold and salt stresses [116].…”