Physiological changes and transcriptome profiling in Saccharum spontaneum L. leaf under water stress and re-watering conditions

Changning Li,Xiupeng Song,Xing Huang,Jinlan Xie,Mukesh Kumar Malviya,Yangrui Li,Zhanghong Mo,Manoj Kumar Solanki,Li Lin,Zhen Wang,Qian Nong

doi:10.1038/s41598-021-85072-1

Abstract

As the polyploidy progenitor of modern sugarcane, Saccharum spontaneum is considered to be a valuable resistance source to various biotic and abiotic stresses. However, little has been reported on the mechanism of drought tolerance in S. spontaneum. Herein, the physiological changes of S. spontaneum GXS87-16 at three water-deficit levels (mild, moderate, and severe) and after re-watering during the elongation stage were investigated. RNA sequencing was utilized for global transcriptome profiling of GXS87-16 under severe drought and re-watered conditions. There were significant alterations in the physiological parameters of GXS87-16 in response to drought stress and then recovered differently after re-watering. A total of 1569 differentially expressed genes (DEGs) associated with water stress and re-watering were identified. Notably, the majority of the DEGs were induced by stress. GO functional annotations and KEGG pathway analysis assigned the DEGs to 47 GO categories and 93 pathway categories. The pathway categories were involved in various processes, such as RNA transport, mRNA surveillance, plant hormone signal transduction, and plant-pathogen interaction. The reliability of the RNA-seq results was confirmed by qRT-PCR. This study shed light on the regulatory processes of drought tolerance in S. spontaneum and identifies useful genes for genetic improvement of drought tolerance in sugarcane.

Highlights

As the polyploidy progenitor of modern sugarcane, Saccharum spontaneum is considered to be a valuable resistance source to various biotic and abiotic stresses
Changes in physiological parameters were determined to verify the effects of water stress, and re-watering (RW) on S. spontaneum leaves
The relative water content (RWC) was restored after RW. H2O2 is a metabolic by-product of reactive oxygen that is an indicator of reactive oxygen species (ROS) removal ability

Summary

Introduction

As the polyploidy progenitor of modern sugarcane, Saccharum spontaneum is considered to be a valuable resistance source to various biotic and abiotic stresses. Plants may increase the synthesis of compatible solutes such as glycine betaine, proline, trehalose, sucrose, or glucose during stress c onditions[3,4] These solutes play diverse functions such as osmotic adjustment, acting as carbon or nitrogen sources, and stabilizing proteins and membranes. Water stress induces the overproduction of reactive oxygen species (ROS), which causes a redox imbalance in the cells This imbalance disrupts the electron transport chain, lipid peroxidation, protein denaturation, and DNA mutation[5]. Abscisic acid (ABA) regulates plant cellular adaptation to drought and other stresses[6,7] Other molecular responses, such as expression of multiple genes, signal transduction, protein synthesis, compounds synthesis, and regulatory loci, play essential roles in drought s tress[8]. Breeders have attempted to develop more stress-resistant cultivars for decades by exploring plant physiological and biochemical processes of drought tolerance. Conventional breeding strategies for crop improvement are limited by the complexity of stress-tolerance traits, lack of efficient selection techniques, and low genetic variance and fertility

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Discussion

Conclusion