Different MicroRNA Families Involved in Regulating High Temperature Stress Response during Cotton (Gossypium hirsutum L.) Anther Development.

Jin Chen,Ao Pan,Pin Su,Xiaoling Yuan,Shengwei Zhu,Shujun He,Zhi Liu

doi:10.3390/ijms21041280

Abstract

MicroRNAs (miRNAs) are small molecule RNAs widely involved in responses to plant abiotic stresses. We performed small RNA sequencing of cotton anthers at four developmental stages under normal and high temperature (NT and HT, respectively) conditions to investigate the stress response characteristics of miRNA to HT. A total of 77 miRNAs, including 33 known miRNAs and 44 novel miRNAs, were identified, and 41 and 28 miRNAs were differentially expressed under NT and HT stress conditions, respectively. The sporogenous cell proliferation (SCP), meiotic phase (MP), microspore release period (MRP), and pollen maturity (PM) stages had 10 (including 12 miRNAs), four (including six miRNAs), four (including five miRNAs), and seven (including 11 miRNAs) HT stress-responsive miRNA families, respectively, which were identified after removing the changes in genotype-specific miRNAs under NT condition. Seven miRNA families (miR2949, miR167, and miR160 at the SCP stage; miR156 and miR172 at the MP stage; miR156 at the MRP stage; and miR393 and miR3476 at the PM stage), which had expression abundance of more than 10% of the total expression abundance, served as the main regulators responding to HT stress with positive or negative regulation patterns. These miRNAs orchestrated the expression of the corresponding target genes and led to different responses in the HT-tolerant and the HT-sensitive lines. The results revealed that the HT stress response of miRNAs in cotton anthers were stage-specific and differed with the development of anthers. Our study may enhance the understanding of the response of miRNAs to HT stress in cotton anthers and may clarify the mechanism of plant tolerance to HT stress.

Highlights

Cotton (Gossypium hirsutum L.) is one of the most economically important crops because its fiber is a raw material used by the textile industry worldwide
Long-term high temperature (HT) stress may result in anther indehiscence, microspore abortion, and premature degeneration of the tapetum [1], which eventually leads to boll shedding, threatening the global cotton production
[5] These results showed that the early stage of anther development may be an important period for miRNAs to participate in the regulation of anther development

Summary

Introduction

Cotton (Gossypium hirsutum L.) is one of the most economically important crops because its fiber is a raw material used by the textile industry worldwide. During the whole process of growth and development, the cotton plant is sensitive to temperature, and the ideal temperature range is 20–30 ◦C. The direct manifestation of climate change is the rise in global temperatures, especially the frequent occurrence of extreme high temperature (HT) during summer, which occurs at the same time as the flowering period of cotton. Long-term HT stress may result in anther indehiscence, microspore abortion, and premature degeneration of the tapetum [1], which eventually leads to boll shedding, threatening the global cotton production. HT stress decreases pollen fertility and crop yield, but the molecular mechanism of the effect of HT stress on plant pollen fertility is still unknown

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Discussion

Conclusion