Shared and tailored common bean transcriptomic responses to combined fusarium wilt and water deficit

Susana T. Leitão,Carmen Santos,Susana de Sousa Araújo,Maria Carlota Vaz Patto,Diego Rubiales

doi:10.1038/s41438-021-00583-2

Abstract

Common bean (Phaseolus vulgaris L.), one of the most consumed food legumes worldwide, is threatened by two main constraints that are found frequently together in nature, water deficit (WD) and fusarium wilt (Fop). To understand the shared and unique responses of common bean to Fop and WD, we analyzed the transcriptomic changes and phenotypic responses in two accessions, one resistant and one susceptible to both stresses, exposed to single and combined stresses. Physiological responses (photosynthetic performance and pigments quantification) and disease progression were also assessed. The combined FopWD imposition negatively affected the photosynthetic performance and increased the susceptible accession disease symptoms. The susceptible accession revealed a higher level of transcriptional changes than the resistant one, and WD single stress triggered the highest transcriptional changes. While 89 differentially expressed genes were identified exclusively in combined stresses for the susceptible accession, 35 were identified in the resistant one. These genes belong mainly to “stress”, “signaling”, “cell wall”, “hormone metabolism”, and “secondary metabolism” functional categories. Among the up-regulated genes with higher expression in the resistant accession, the cysteine-rich secretory, antigen 5 and Pr-1 (CAP) superfamily protein, a ribulose bisphosphate carboxylase family protein, and a chitinase A seem promising targets for multiple stress breeding.

Highlights

In nature, plants are simultaneously exposed to a combination of different stresses that influence both crop growth and productivity
A better knowledge of the molecular mechanisms behind plant multiple stress interactions is important for a more precise breeding because plants exhibit tailored physiological and molecular responses when exposed to simultaneous stresses, which are not the addition of the responses observed in individual stresses imposition[10]
Few studies exist on the interaction of abiotic and biotic stresses in this crop, and a scarce understanding of key genes and signaling pathways triggered by concurrent stresses is available

Summary

Introduction

Plants are simultaneously exposed to a combination of different stresses that influence both crop growth and productivity. Global warming is increasing the frequency of heatwaves, especially in the Mediterranean area and facilitating pathogen spread, altering the habitat range of pathogens[1]. This forecasted chance to be exposed to multi-stress interactions[2] is a challenge for plant breeding programs. It is essential and urgent to better understand the molecular mechanisms used by grain legumes to improve fitness by balance growth and defense against diverse combinations of environmental constraints[6]. The response of plants to simultaneous stress conditions is of particular interest, as one stress response pathway might interact and antagonize another, a process mainly controlled by phytohormones[4]. The tradeoff between development and defense under abiotic and biotic stress conditions relies on soluble sugars, transcription factors activation, and interconnected signaling pathways, including Ca2+

Methods

Results

Conclusion