Research Article <i>Bradyrhizobium</i> spp. as attenuators of water deficit stress in runner peanut genotypes based on physiological and gene expression responses

Abstract

The peanut plant has high plasticity and great adaptability to adverse conditions, including drought. To mitigate the negative effects of drought on legumes, nitrogen-fixing microorganisms have been investigated in some plant species, such as soybeans and beans. We analyzed the role Bradyrhizobium strains in peanut genotypes subjected to water deficit by means of plant growth, physiological and gene expression analysis. The research was conducted under greenhouse conditions with the runner peanut genotypes (IAC Runner 886, 2012-33 and 2012-47) and two Bradyrhizobium strains (ESA 123 and SEMIA 6144). After 20 days of germination, the water supply was completely interrupted and gas exchange analysis were carried out using an infrared gas analyzer, up to the 10 th day of stress. Leaves were collected for the analysis of proline content and the expression of NCED and ERF8 genes. Analyses of plant height (PH), shoot dry mass (SDM), root dry mass (RDM), number of nodules (NN) and nodule weight (NW) also were ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 18 (4): gmr18379 S.L. Brito et al. 2 performed. The peanut shoots inoculated with the Bradyrhizobium strains obtained the best results. The genotypes inoculated with the ESA 123 strain obtained superior responses compared to the nonstressed treatment inoculated with the same bacteria and the stressed control without bacterial inoculation. In the ESA 123 inoculated treatments, the water stressed plants had higher RDM (28.5% higher, on average), NN (two fold higher), and gene expression (approximately six and threefold higher for ERF8 and NCED genes, respectively). The increase in the expression of NCED and ERF8 genes, in the three genotypes inoculated with ESA 123, suggests a key role of this inoculant in the activation of metabolic cascades for plant protection under water deficit.

Bacilli Rhizobacteria as Biostimulants of Growth and Production of Sesame Cultivars under Water Deficit

“…However, pant001 was the strain that provided the highest mean among the inoculated treatments ( Figure 4 d). In an experiment with peanut genotypes treated with bacterial strains and under water deficit, minimal differences were observed in relation to water restriction [ 41 ]. Despite the plants showing reductions in root growth, the bacterial strains were efficient in promoting growth and water deficit attenuation, emphasizing the importance of using inoculants to mitigate the effects of water deficit [ 12 , 41 ].…”

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

“…Recent studies have revealed that the application of plant growth-promoting bacteria (PGPB), like to the genera Bacillus spp. and Bradyrhizobium spp., can be used as a strategy to mitigate water stress ( Brito et al., 2019 ; Lastochkina et al., 2019 ). The interaction between plants and microorganisms can also enhance the plant’s tolerance to water deficit, as already assessed in crops such as maize ( Kavamura et al., 2013 ; Santos et al., 2020 ), sorghum ( Santana et al., 2020 ), wheat ( Gontia-Mishra et al., 2016 ), foxtail millet ( Niu et al., 2018 ), tomato ( Gowtham et al., 2020 ), and more recently in sesame ( Lima et al., 2023 ).…”

Effect of fungicides on the symbiosis between Bradyrhizobium strains and peanut

“…Peanut (Arachis hypogaea L.) can efficiently associate with rhizobia lineages, but is more efficient with the Bradyrhizobium genus (Valetti et al 2016, Barbosa et al 2018, Brito et al 2019. Crop yield can be maximized by using inoculants containing competent strains, favoring the crop management by small producers (Sizenando et al 2016, Valetti et al 2016.…”