Transcriptional Changes in Pearl Millet Leaves under Heat Stress.

Jianan Tang,Haidong Yan,Huan Zhang,Min Sun,Jishan Chen,Chuang Lin,Ailing Zhang,Jian Zhang,Linkai Huang,Xiaoshan Wang,Dejun Huang,Xiaowen Lu

doi:10.3390/genes12111716

Jianan Tang, Haidong Yan + Show 10 more

Open Access

https://doi.org/10.3390/genes12111716

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Abstract

High-temperature stress negatively affects the growth and development of plants, and therefore threatens global agricultural safety. Cultivating stress-tolerant plants is the current objective of plant breeding programs. Pearl millet is a multi-purpose plant, commonly used as a forage but also an important food staple. This crop is very heat-resistant and has a higher net assimilation rate than corn under high-temperature stress. However, the response of heat resistant pearl millet has so far not been studied at the transcriptional level. In this study, transcriptome sequencing of pearl millet leaves exposed to different lengths of heat treatment (1 h, 48 h and 96 h) was conducted in order to investigate the molecular mechanisms of the heat stress response and to identify key genes related to heat stress. The results showed that the amount of heat stress-induced DEGs in leaves differs with the length of exposure to high temperatures. The highest value of DEGs (8286) was observed for the group exposed to heat stress for 96 h, while the other two treatments showed lower DEGs values of 4659 DEGs after 1 h exposure and 3981 DEGs after 48 h exposure to heat stress. The DEGs were mainly synthesized in protein folding pathways under high-temperature stress after 1 h exposure. Moreover, a large number of genes encoding ROS scavenging enzymes were activated under heat stress for 1 h and 48 h treatments. The flavonoid synthesis pathway of pearl millet was enriched after heat stress for 96 h. This study analyzed the transcription dynamics under short to long-term heat stress to provide a theoretical basis for the heat resistance response of pearl millet.

Highlights

High temperature is one of the stress factors often encountered in the growth cycle of plants
When pearl millet seedlings were subjected to heat stress, 4659 genes were involved in the short-term heat stress response process, the expression of 3981 genes was affected during medium-term heat stress, and 8286 DEGs play a role in the long-term heat stress
In order to explore the molecular mechanism of heat stress response of pearl, we performed transcriptome sequencing on the leaves of pearl millet after heat stress exposure of 1 h, 48 h and 96 h

Summary

Introduction

High temperature is one of the stress factors often encountered in the growth cycle of plants. High temperature can cause degradation of heat-denatured abnormal proteins, damage the function of the cell membrane, cause plant cell damage or even cell death, thereby inhibiting plant growth and threatening food safety [1]. The production of millet and sorghum will decrease by 10–20% and 5–15%, respectively, with losses of 2.33–4.02 billion USD and. High temperature can lead to the death of several plant species, such as Centaurea cyanus, Lilium brownii var. Previous studies on plant heat stress mainly have two treatment methods [4]. Plants are exposed to heat stress 10–15 ◦ C higher than the optimum growth temperature for a short time (heat shock treatment) [1], and plants are exposed to heat stress higher than the optimal growth temperature of 2.5 ◦ C for a long time (prolonged warming) [5]

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