Drought is one of the environmental factors that most affects peanut cultivation in semi-arid regions, resulting in economic losses to growers. However, growth promoting bacteria are able to reduce water deficit damage in some plant species. In this context, this study aimed to evaluate the interaction of Bradyrhizobium strains reducing water stress effects on peanut genotypes by antioxidant enzymes activities, leaf gas exchanges and vegetative growth, as well as to determine the taxonomic positioning of strain ESA 123. The 16S rRNA gene of ESA 123 was amplified by PCR and sequenced by dideoxy Sanger sequencing method. An experiment was performed in greenhouse with three peanut genotypes (BRS Havana, CNPA 76 AM and 2012-4), two Bradyrhizobium strains (SEMIA 6144 and ESA 123), a mineral source of N and an absolute control (without N) under two water regimes (with and without irrigation). Seeds of peanut were sown and the plants were grown until 30 days after emergence. On the 20th day, the water deficit plants group had their irrigation suspended for 10 days. At in silico analyzes, ESA 123 presented 98.97% similarity with the type strain of B. kavangense. Leaf gas exchange was affected by water deficit; as well as alteration of antioxidant activities and reduction of vegetative growth variables. However, some plants inoculated with SEMIA 6144 and ESA 123 strains presented lower reductions and increment of some evaluated variables, mainly the ones inoculated with the ESA 123 strain, Bradyrhizobium sp. from the semi-arid region of Northeast Brazil. This data suggests beneficial effects of the peanut-Bradyrhizobium interaction in a water stress condition, specially with the ESA 123 strain.
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.
As queimadas nos ecossistemas naturais ocorrem de forma frequente e descontrolada, principalmente devido às ações antrópicas. Este trabalho objetivou analisar o tempo de letalidade do câmbio da casca na temperatura de 60 °C em duas espécies florestais, Tachigali paniculata Aubl. (carvoeiro) e Cecropia pachystachya Trécul (embaúba), ambas nativas do bioma Cerrado. Coletaram-se amostras de 10 árvores, distribuídas em duas classes diamétricas de 5 ┤15 e 15 ┤25 cm, contendo cinco indivíduos em cada classe. Foram retiradas amostras de 10 x 10 cm da casca (floema + periderme) de cada árvore, na altura do peito (DAP) de ambas as espécies. Após a verificação dos pressupostos de normalidade e de homogeneidade de variâncias residuais, os dados foram submetidos à análise de regressão para verificar as variáveis interligadas à resistência do câmbio a exposição ao fogo. Cecropia pachystachya (embaúba) apresentou uma espessura de casca de 2,40 mm a 6,53 mm e tempo de 55 segundos a 2 minutos e 23 segundos para que câmbio atingisse a temperatura letal de 60°C, enquanto para espécie Tachigali paniculata (carvoeiro) obteve uma espessura de casca que variou de 4,97 a 15,60 mm e o tempo de 1 minuto e 26 segundos a 4 minutos 19 segundos para a letalidades do câmbio. Portanto, o carvoeiro é 65% mais resistente ao calor do fogo, quando comparada com embaúba. Desse modo, as espécies florestais com maior espessura de casca apresentam maior tempo de resistência a exposição de incêndios florestais, sendo que a presença da casca (floema + periderme) são cruciais para a sobrevivência das espécies do Bioma Cerrado.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.