Key Soybean Seedlings Drought-Responsive Genes and Pathways Revealed by Comparative Transcriptome Analyses of Two Cultivars.

Huidong Xuan,Na Guo,Sushuang Deng,Li Zhou,Haitang Wang,Yanzhong Huang,Congcong Wang,Han Xing,Jianyu Xu,Jinming Zhao

doi:10.3390/ijms23052893

Huidong Xuan, Na Guo + Show 8 more

Open Access

https://doi.org/10.3390/ijms23052893

Copy DOI

Abstract

Seedling drought stress is one of the most important constraints affecting soybean yield and quality. To unravel the molecular mechanisms under soybean drought tolerance, we conducted comprehensive comparative transcriptome analyses of drought-tolerant genotype Jindou 21 (JD) and drought-sensitive genotype Tianlong No.1 (N1) seedlings that had been exposed to drought treatment. A total of 6038 and 4112 differentially expressed genes (DEGs) were identified in drought-tolerant JD and drought-sensitive N1, respectively. Subsequent KEGG pathway analyses showed that numerous DEGs in JD are predominately involved in signal transduction pathways, including plant hormone signaling pathway, calcium signaling pathway, and MAPK signaling pathway. Interestingly, JA and BR plant hormone signal transduction pathways were found specifically participating in drought-tolerant JD. Meanwhile, the differentially expressed CPKs, CIPKs, MAPKs, and MAP3Ks of calcium and MAPK signaling pathway were only identified in JD. The number of DEGs involved in transcription factors (TFs) is larger in JD than that of in N1. Moreover, some differently expressed transcriptional factor genes were only identified in drought-tolerant JD, including FAR1, RAV, LSD1, EIL, and HB-PHD. In addition, this study suggested that JD could respond to drought stress by regulating the cell wall remodeling and stress-related protein genes such as EXPs, CALSs, CBPs, BBXs, and RD22s. JD is more drought tolerant than N1 owing to more DEGs being involved in multiple signal transduction pathways (JA, BR, calcium, MAPK signaling pathway), stress-related TFs, and proteins. The above valuable genes and pathways will deepen the understanding of the molecular mechanisms under drought stress in soybean.

Highlights

Soybean (Glycine max [L.] Merr.) has been adopted as one of the most important economic and oil crops worldwide
Through the analysis of the expression patterns of XTHs in two soybean gen with different drought tolerance, we found that the XTHs were significantly dow lated by drought stress in soybean, and the number of down-regulated XTHs in results showed that a large number of up-regulated EXPs and CALS5 in Jindou 21 (JD) may produce a large amount of related proteins under drought stress, so that the cell wall could alleviate the damage caused by drought stress, and the drought tolerance of JD is stronger than N1 at seedling stage
It is generally believed that callose is produced by callose synthase (CALS) in the cell walls of many higher plants and plays an important role in plant development and/or response to a variety of biotic and abiotic stress [66,67] The present study showed that the expression of one CALS3 was down-regulated in both varieties, while the expressions of two CALS5 were significantly up-regulated in JD

Summary

Introduction

Soybean (Glycine max [L.] Merr.) has been adopted as one of the most important economic and oil crops worldwide. It provides human beings with major plant oils, proteins, macronutrients, minerals, and isoflavones [1,2]. There are several environmental challenges including biotic and abiotic stresses. Drought stress is gradually increasing with the changes of global climatic conditions [3]. Studies have reported that drought can significantly reduce the yield of soybean by 24–50%, or more seriously by 80% or higher [4,5]. Efforts need to be made to understand the potential molecular mechanisms and genes which are related to soybean drought tolerance

Results

Discussion

Conclusion