Transcriptome sequencing revealed the molecular mechanism of response of pearl millet root to heat stress

Abstract

Temperature is an abiotic stressor often encountered in the life cycle of plants. High temperature can affect the growth and development of plants (Suraweera et al., 2020). According to a previous report (PICC 2014; http://www.ipcc.ch/), by the end of this century, the average temperature will increase by a maximum of approximately 4°C, and the temperature will increase by 0.2°C every ten years. Global warming will reduce the average output of millet and sorghum by 10%-20%(2.33-4.02 billion USD) and 5%-15% (0.73-2.17 billion USD), respectively (Sultan et al., 2019). Therefore, understanding the response mechanism of plants to heat stress (HS) is particularly important for the cultivation of plants with strong resistance and adaptability.Recently, many studies have focussed on revealing mechanisms responsive to HS for plant aboveground organs, but studies on the response of plant roots under HS are limited (Xu & Huang, 2008).HS has more extensive effect on roots than stems and will affect the growth and yield of the whole plant (Guedira & Paulsen, 2002). Sailaja and Anjum (Sailaja et al., 2014) studied the gene expression in the heat-tolerant rice cultivar N22 and the heat-susceptible rice cultivar Vandana under HS (42/36°C, day/night). It was found that compared with Vandana, N22 root tissue had a larger number of differentially expressed genes (DEGs) under short-term (24 hr) and long-term (5 day) HS conditions, indicating that roots play an important role in heat tolerance. Thus, plant root tissues would be more suitable and significant to study response mechanism to HS. Pearl millet (Pennisetum glaucum (L.) R. Br.) is the sixth largest cereal crop (Khan et al., 2019; Sun et al., 2020) and an ideal plant for sustainable alternative energy (Yadav et al., 2011) (https://biofu els.ifas. uf.edu/pearl-millet.shtml). More than 90 million people relay on pearl

Genetic and molecular mechanisms underlying root architecture and function under heat stress—A hidden story

“…Several investigations have been carried out to identify and characterize the candidate genes/proteins and small RNAs involved in the root's response to thermal stress. A root‐specific transcriptomic‐based differentially expressed genes analysis was conducted in 13‐day‐old seedlings of Pennisetum glaucum (pearl millet) exposed to short‐duration heat stress [40/35°C and control (26/21°C) for 7 h; root tissue harvested at 1, 3 and 7 h] (R. Sun et al, 2021). The analysis revealed that HSFs and the endoplasmic reticulum stress pathway were mainly affected after 1 h of heat stress (R. Sun et al, 2021).…”

Transcriptional Changes in Pearl Millet Leaves under Heat Stress

“…The experimental conditions of the control group were set to 26 • C for 14 h under light and at 21 • C for 10 h in the dark. The conditions of the heat treatment group were 40 • C for 14 h under light and 10 h in the dark at 35 • C [6]. 50% Hoagland nutrition mix (1 mM MgSO 4 , 1 mM KH 2 PO 4 , 1 mM NH 4 NO 3 , 0.5 mM CaCl 2 , 0.1 mM FeNa-EDTA, 25 mM NaCl, 0.1 mM H 3 BO 3 , 0.1 mM Na 2 SiO 3 , 1.5 µM CuSO 4 , 50 µM KCl, 10 µM MnSO 4 , 0.075 µM Na 2 MoO 4 and 2 µM ZnSO 4 ) was used to provide nutrients throughout the cultivation stage and treatment period of the plant.…”

“…The production of pearl millet (Pennisetum glaucum (L.) R. Br) is the sixth largest cereal crop, right after wheat, rice, corn, sorghum and barley production [6]. Its planting area reaches 31 million hectares, which provides food and income sources of 90 million people (ICRISAT; https://www.icrisat.org/, 21 July 2021).…”

Differential transcriptomic responses to heat stress in surface and subterranean diving beetles

“…The former scenario would reflect the reduced thermal tolerance of P. macrosturtensis, which is also supported by the species differentially expressing a far lower number of genes in response to higher temperatures compared to P. nigroadumbratus. Similarly reduced numbers of differentially expressed genes have also been associated with lower thermal tolerances in other organisms such as fish (Narum & Campbell, 2015), lizards (Akashi et al, 2016), rotifers (Paraskevopoulou et al, 2020, red algae (W. Wang et al, 2018), and plants (Jin et al, 2020;Sun et al, 2021), though we note the inverse (or alternatively, no clear pattern) has been observed in a number of cases, potentially reflecting lower levels of stress as opposed to an inability to mount a HSR (DeBiasse & Kelly, 2016;Perez et al, 2021).…”