Understanding the Impact of Drought in Coffea Genotypes: Transcriptomic Analysis Supports a Common High Resilience to Moderate Water Deficit but a Genotype Dependent Sensitivity to Severe Water Deficit

Fábio M Damatta,Fernando C Lidon,Dora Batista,José C Ramalho,Isabel Fernandes,Fábio L Partelli,Octávio S Paulo,Isabel Marques,Ana I Ribeiro-Barros

doi:10.3390/agronomy11112255

Abstract

Water scarcity is the most significant factor limiting coffee production, although some cultivars can still have important drought tolerance. This study analyzed leaf transcriptomes of two coffee cultivars with contrasting physiological responses, Coffea canephora cv. CL153 and Coffea. arabica cv. Icatu, subjected to moderate (MWD) or severe water deficits (SWD). We found that MWD had a low impact compared with SWD, where 10% of all genes in Icatu and 17% in CL153 reacted to drought, being mainly down-regulated upon stress. Drought triggered a genotype-specific response involving the up-regulation of reticuline oxidase genes in CL153 and heat shock proteins in Icatu. Responsiveness to drought also included desiccation protectant genes, but primarily, aspartic proteases, especially in CL153. A total of 83 Transcription Factors were found engaged in response to drought, mainly up-regulated, especially under SWD. Together with the enrollment of 49 phosphatases and 272 protein kinases, results suggest the involvement of ABA-signaling processes in drought acclimation. The integration of these findings with complementing physiological and biochemical studies reveals that both genotypes are more resilient to moderate drought than previously thought and suggests the existence of post-transcriptional mechanisms modulating the response to drought.

Highlights

Introduction conditions of the Creative CommonsAlong with the rapid expansion in population and global warming, water scarcity has become a worldwide challenge for agriculture [1,2,3]
Upon subjecting the plants to a gradual moderate or severe water deficit, we identified the transcriptomic mechanisms of drought tolerance in these genotypes
Differential Gene Changes of CL153 and Icatu in Response to Drought In CL153, the lowest number of expressed genes was found under moderate water deficit (MWD) (20052) and the highest under WW conditions (20528; Figure 1; Table S2)

Summary

Introduction

Introduction conditions of the Creative CommonsAlong with the rapid expansion in population and global warming, water scarcity has become a worldwide challenge for agriculture [1,2,3]. To cope with water deficits, plants trigger a wide range of responses at the molecular, biochemical, and physiological. A response to drought usually includes transcriptional and post-transcriptional modulations that lead to a differential expression of genes and pathways, which promote metabolic and physiological changes associated with plant acclimation [6,7,8]. The first group includes water channel proteins and membrane transporters [9], key enzymes for osmolyte biosynthesis (e.g., proline, sugars) [10], detoxification enzymes (e.g., catalase, superoxide dismutase, ascorbate peroxidase) [8], enzymes for fatty acid metabolism, ferritin, and lipid-transfer proteins [11], and proteins for the protection of macromolecules (e.g., late embryogenesis abundant, antifreeze proteins and chaperones) [12]. A second important group of responsive drought-induced genes that are activated by drought include transcription factors (TFs) as the widely known dehydration responsive element binding (DREB)

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Conclusion