Molecular and biochemical responses of sesame (Sesame indicum L.) to rhizobacteria inoculation under water deficit

Anderson Reges Dos Santos; Geisenilma Maria Gonçalves da Rocha; Alexandre Paulo Machado; Paulo Ivan Fernandes-Junior; Nair Helena Castro Arriel; Tarcisio Marcos de Souza Gondim; Liziane Maria de Lima

doi:10.3389/fpls.2023.1324643

Molecular and biochemical responses of sesame (Sesame indicum L.) to rhizobacteria inoculation under water deficit

Front Plant Sci. 2024 Jan 18:14:1324643. doi: 10.3389/fpls.2023.1324643. eCollection 2023.

Authors

Anderson Reges Dos Santos¹, Geisenilma Maria Gonçalves da Rocha², Alexandre Paulo Machado³, Paulo Ivan Fernandes-Junior⁴, Nair Helena Castro Arriel⁵, Tarcisio Marcos de Souza Gondim⁵, Liziane Maria de Lima⁵

Affiliations

¹ Master's Degree in Agricultural Sciences, State University of Paraiba (UEPB), Campina Grande, PB, Brazil.
² Postdoc, Embrapa Algodão, Campina Grande, PB, Brazil.
³ Department of Basic Health Sciences, Federal University of Mato Grosso, Cuibá, MT, Brazil.
⁴ Embrapa Semiárido, Petrolina, PE, Brazil.
⁵ Embrapa Algodão, Campina Grande, PB, Brazil.

Abstract

Introduction: Water scarcity is a challenge for sesame cultivation under rainfed conditions. In this scenario, a potential strategy to alleviate the water deficit is the application of plant growth-promoting bacteria. The objective of this study was to analyze the interaction of rhizobacteria with sesame cultivation under water deficit conditions.

Methods: An experiment was conducted in pots in a greenhouse using the BRS Morena sesame cultivar. The experimental design was completely randomized in a factorial scheme: 2 (irrigation regimes - daily irrigation and water deficit by suspending irrigation until 90% stomatal closure) x 6 (treatments with nitrogen or inoculants), with 5 replications. The types of fertilization were characterized by the addition of nitrogen (ammonium sulfate; 21% N), inoculants based on Bacillus spp. (pant001, ESA 13, and ESA 402), Agrobacterium sp. (ESA 441), and without nitrogen (control). On the fifth day after the suspension of irrigation, plant material was collected for gene expression analysis (DREB1 and HDZ7), activities of antioxidant enzymes (superoxide dismutase and catalase), relative proline content, and photosynthetic pigments. At the end of the crop cycle (about 85 days), production characteristics (root dry matter, aboveground dry matter, number of capsules, and thousand seed weight), as well as leaf nitrogen (N) and phosphorus (P) content, were evaluated.

Results and discussion: There was a positive effect on both production and biochemical characteristics (proline, superoxide dismutase, catalase, and photosynthetic pigments). Regarding gene expression, most of the inoculated treatments exhibited increased expression of the DREB1 and HDZ7 genes. These biological indicators demonstrate the potential of rhizobacteria for application in sesame cultivation, providing nutritional supply and reducing the effects of water deficit.

Keywords: DREB1 and HDZ7 genes; antioxidant enzymes; diazotrophic bacteria; drought; symbiosis.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This research received financial support from Agricultural Research Corporation (Embrapa, SEG 20.18.01.021.00.00) and Graduate Development Program (PDPG) - Strategic Partnerships in States III, Notice No. 38/2022, Paraiba State Research Foundation (FAPESQ), Grant Agreement No. 397/2023.