Transcriptome-Based Identification and Functional Characterization of NAC Transcription Factors Responsive to Drought Stress in Capsicum annuum L.

Frontiers in Genetics, vol. 12, pp. 743902

Abstract

Capsicum annuum L. is one of the most cultivated Solanaceae species, and in the open field, water limitation leading to drought stress affects its fruit quality, fruit setting, fruit size and ultimately yield. We identified stage-specific and a common core set of differentially expressed genes, following RNA-seq transcriptome analyses of a breeding line subjected to acute drought stress followed by recovery (rewatering), at three stages of plant development. Among them, two NAC transcription factor (TF) genes, i.e., CaNAC072 and CaNAC104, were always upregulated after drought stress and downregulated after recovery. The two TF proteins were observed to be localized in the nucleus following their transient expression in Nicotiana benthamiana leaves. The expression of the two NACs was also induced by NaCl, polyethylene glycol (PEG) and abscisic acid (ABA) treatments, suggesting that CaNAC072 is an early, while CaNAC104 is a late abiotic stress-responsive gene. Virus-induced gene silencing (VIGS) of CaNAC104 did not affect the pepper plantlet’s tolerance to drought stress, while VIGS of CaNAC072 increased drought tolerance. Heterologous expression of CaNAC072 in Arabidopsis thaliana as well as in plants mutated for its homolog ANAC072 did not increase drought stress tolerance. This highlights a different role of the two NAC homologs in the two species. Here, we discuss the complex role of NACs as transcriptional switches in the response to drought stress in bell pepper.

Authors 8

1. Dionís Borràs

   University of Turin

   Affiliation as printed

   Department of Agricultural, Forest and Food Sciences, Plant Genetics and Breeding, University of Torino, Turin, Italy

2. Lorenzo Barchi

   University of Turin

   Affiliation as printed

   Department of Agricultural, Forest and Food Sciences, Plant Genetics and Breeding, University of Torino, Turin, Italy

3. Karina Schulz

   Max Planck Institute of Molecular Plant Physiology

   Affiliation as printed

   Max Planck Institute of Molecular Plant Physiology, Potsdam, Germany

4. Andrea Moglia

   University of Turin

   Affiliation as printed

   Department of Agricultural, Forest and Food Sciences, Plant Genetics and Breeding, University of Torino, Turin, Italy

5. Alberto Acquadro

   University of Turin

   Affiliation as printed

   Department of Agricultural, Forest and Food Sciences, Plant Genetics and Breeding, University of Torino, Turin, Italy

6. Iman Kamranfar

   University of Potsdam

   Affiliation as printed

   Department Molecular Biology, Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany

7. Salma Balazadeh Aachen Plant Sciences and Natural Products Institute of Biology Leiden

   Leiden University · Max Planck Institute of Molecular Plant Physiology

   Affiliation as printed

   Max Planck Institute of Molecular Plant Physiology, Potsdam, Germany

   Plant Sciences and Natural Products, Institute of Biology Leiden (IBL), Leiden University, Leiden, Netherlands

8. Sergio Lanteri corresponding

   University of Turin

   Affiliation as printed

   Department of Agricultural, Forest and Food Sciences, Plant Genetics and Breeding, University of Torino, Turin, Italy