Transcriptional profile dynamics of two contrasting sugarcane cultivars in response to drought stress submitted to prolonged water deficit

Author(s)

Daniela Konrad

• Document type: Master's Dissertation
• Press: Jaboticabal. 2019-12-05.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Ciências Agrárias e Veterinárias. Jaboticabal
• Defense date: 2019-10-18
• Advisor: Maria Ines Tiraboschi Ferro; Juliana da Silva Vantini

Abstract

Extended periods of drought have become more frequent in some regions of Brazil. In addition, the expansion of sugarcane cultivation to regions with prolonged water deficiency makes sugarcane production limited at these locations. The best way around this problem is to use stress-tolerant cultivars. In this work, the sugarcane gene expression profile was evaluated from two cultivars with contrasting responses to water deficit: one of them with tolerant behavior (SP81-3250), and the other highly demanding in water (RB855453 ), considered sensitive. Both were submitted to three soil water potentials (control (without water stress), moderate water deficit and severe water deficit) from 60 days after planting. These plants were evaluated molecularly and physiologically at three different times: 30, 60 and 90 days after the application of the treatments. This is one of the few studies carried out so far on the response of sugarcane plants under prolonged water deficit. This stress was realized during the period known as sugarcane formation phase, comprising the most critical period by water demand. The overall analysis of gene expression through RNA-Seq technology showed significant changes in response to water deficit between the two cultivars. The transcripts of the tolerant genotype showed a higher reaction capacity of the plants to prolonged water deficit, while in the sensitive genotype, several plant survival mechanisms were repressed. The tolerant cultivar presented induction of transcripts associated with carbohydrate transport and metabolism, transcription and energy production. In the most severe stress, the tolerant cultivar showed, in contrast to the sensitive one, the induction of sucrose accumulation by several ways, showing a conservation of this sugar despite the stress. Moreover, in the differential expression analysis of glutathione metabolism enzymes, whose important role in abiotic stress conditions has been widely discussed in the most different plants, there was a greater induction of glutathione production enzymes in tolerant cultivar compared to sensitive. Some unannotated differentially expressed transcripts were detected and could be studied to analyze their role in tolerance to water deficit. The results bring new information for understanding and improvement aimed at increasing tolerance to prolonged water deficit in sugarcane. (AU)

• FAPESP's process: 18/01326-0 - Dynamics of the transcriptional profile of two sugarcane cultivars contrasting the dry and submitted to the prolonged water deficit
• Grantee: Daniela Konrad
• Support Opportunities: Scholarships in Brazil - Master