O ácido hexanoico pode modular o metabolismo antioxidante e o metabolismo nitrosativo em cafeeiro
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Data
2019-04-24
Autores
Calzado, Natália Fermino [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
As plantas em seu ambiente respondem a uma infinidade complexa de fatores que podem romper sua homeostase fisiológica. Com relação aos estresses abióticos, a capacidade de organismos vegetais responderem a esses estresses é flexível e depende do balanceamento da interação entre moléculas de sinalização. Destacam-se entre as moleculas sinalizadora em plantas as espécies reativas de oxigênio (EROs) e espécies reativas de nitrogênio (ERNs), que estão envolvidos na aclimatação a estresses abióticos. O transporte, a biossíntese e o metabolismo de EROs e ERNs influenciam os mecanismos de resposta das plantas ao ambiente. Um elemento chave na geração de EROs em plantas são a NADPH oxidases, que são enzimas codificadas por uma família gênica em plantas, pouco estudada do ponto de vista evolutivo. Já um elemento regulador importante da homeostase de ERNs em plantas são as S-nitrosoglutationa redutases, enzimas também pouco estudadas do ponto de vista evolutivo. Nos últimos anos, diversos trabalhos sugerem que as plantas podem ser elicitadas por compostos químicos para melhor tolerar estresses abióticos. No entanto, os mecanismos de reprogramação fisiológica e transcricional por trás destes sinalizadores ainda são pouco conhecidos. O ácido hexanoico é um ácido carboxílico que, em baixas concentrações, possui um efeito indutor de resistência e modulador do metabolismo em diversos sistemas vegetais. No entanto, o impacto do ácido hexanoico na geração de EROs e de ERNs nunca foi avaliado. Neste projeto, testamos a hipótese de que o ácido hexanoico pode induzir a produção de EROs e ERNs em sistemas vegetais, por meio de sua aplicação em cafeeiro (Coffea arabica L.). C. arabica é um sistema vegetal tetraploide que, a despeito de sua importância econômica e social no Brasil e em países em desenvolvimento, carece de estudos bioquímicos e moleculares com impacto em sua fisiologia. Identificamos in silico genes codificantes para enzimas chave no processo de formação de EROs e ERNs, Rboh e GSNOR, para as espécies Coffea canephora, Coffea arabica, Coffea eugenioides e outras 24 espécies vegetais. Para todas as espécies foi investigado o perfil de seleção evolutiva para estes genes, assim como os perfis transcricionais em espécies selecionadas. Também avaliamos o efeito da aplicação de ácido hexanoico em solução nutritiva no metabolismo oxidativo e nitrosativo, bem como avaliamos transcricionalmente genes-chave na modulação destes processos. Observamos que a aplicação de ácido hexanoico em solução nutritiva induz a formação de peróxido de hidrogênio e S-nitrosotiois, bem promove a modulação diferencial de genes-chave em função do subgenoma ao qual pertencem. Com isso, o presente trabalho traz importantes subsídios para a compreensão da dinâmica molecular de eventos associados à aclimatação ao estresse mediados por eliciadores químicos.
Plants in their environment respond to a complex infinity of factors that can interfere their physiological homeostasis. Regarding abiotic stresses, the ability of plants to respond to these stresses is flexible and depends on balancing the interaction among signaling molecules. Among the signaling molecules in plants, we highlight reactive oxygen species (ROS) and reactive nitrogen species (RNS), which are involved in acclimatization to abiotic stresses. The transport, biosynthesis and metabolism of ROS and ERNs influence plant response mechanisms to the environment. A key element in the generation of EROs in plants are NADPH oxidases, which are enzymes encoded by a gene family in plants, that is scarcely studied in an evolutionary approach. An important regulator of the homeostasis of plant ERNs is S-nitrosoglutathione reductase, which is also a poorly addressed enzyme in terms of evolutionary studies. Recently, several studies have suggested that plants can be elicited by chemical compounds, to better tolerate abiotic stresses. However, the mechanisms of physiological and transcriptional reprogramming behind these signaling molecules are still poorly understood. Hexanoic acid is a carboxylic acid, which, at low concentrations, can induce resistance to stresses and it can also modulate metabolism on numerous plant systems. However, the impact of hexanoic acid on the generation of ROS and ERNs has never been evaluated. In this project, we tested the hypothesis if hexanoic acid can induce the production of ROS and ERNs in plant systems, through its application in coffee plants (Coffea arabica L.). C. arabica is a tetraploid plant that, despite its economic and social importance in Brazil and in developing countries, lacks biochemical and molecular studies with impact on its physiology. We identified in silico genes encoding key enzymes in the process of formation of EROs and ERNs, Rboh and GSNOR, in C. canephora, C. arabica, C. eugenioides and 24 other plant species. For all species, the evolutionary selection profile for these genes was investigated, as well as the transcriptional profiles in selected species. We also evaluated the effect of the application of hexanoic acid in nutrient solution on oxidative and nitrosative metabolism, as well as evaluated transcriptional patterns of key genes in the modulation of these processes in C. arabica. We observed that the application of hexanoic acid in nutrient solution induces the formation of hydrogen peroxide and S-nitrosothiols, as well as differentially modulate of key genes in function of the subgenome to which they belong. Overall, the present work provides important insights on the understanding of the molecular dynamics of events associated with acclimatization to stress mediated by chemical elicitors.
Plants in their environment respond to a complex infinity of factors that can interfere their physiological homeostasis. Regarding abiotic stresses, the ability of plants to respond to these stresses is flexible and depends on balancing the interaction among signaling molecules. Among the signaling molecules in plants, we highlight reactive oxygen species (ROS) and reactive nitrogen species (RNS), which are involved in acclimatization to abiotic stresses. The transport, biosynthesis and metabolism of ROS and ERNs influence plant response mechanisms to the environment. A key element in the generation of EROs in plants are NADPH oxidases, which are enzymes encoded by a gene family in plants, that is scarcely studied in an evolutionary approach. An important regulator of the homeostasis of plant ERNs is S-nitrosoglutathione reductase, which is also a poorly addressed enzyme in terms of evolutionary studies. Recently, several studies have suggested that plants can be elicited by chemical compounds, to better tolerate abiotic stresses. However, the mechanisms of physiological and transcriptional reprogramming behind these signaling molecules are still poorly understood. Hexanoic acid is a carboxylic acid, which, at low concentrations, can induce resistance to stresses and it can also modulate metabolism on numerous plant systems. However, the impact of hexanoic acid on the generation of ROS and ERNs has never been evaluated. In this project, we tested the hypothesis if hexanoic acid can induce the production of ROS and ERNs in plant systems, through its application in coffee plants (Coffea arabica L.). C. arabica is a tetraploid plant that, despite its economic and social importance in Brazil and in developing countries, lacks biochemical and molecular studies with impact on its physiology. We identified in silico genes encoding key enzymes in the process of formation of EROs and ERNs, Rboh and GSNOR, in C. canephora, C. arabica, C. eugenioides and 24 other plant species. For all species, the evolutionary selection profile for these genes was investigated, as well as the transcriptional profiles in selected species. We also evaluated the effect of the application of hexanoic acid in nutrient solution on oxidative and nitrosative metabolism, as well as evaluated transcriptional patterns of key genes in the modulation of these processes in C. arabica. We observed that the application of hexanoic acid in nutrient solution induces the formation of hydrogen peroxide and S-nitrosothiols, as well as differentially modulate of key genes in function of the subgenome to which they belong. Overall, the present work provides important insights on the understanding of the molecular dynamics of events associated with acclimatization to stress mediated by chemical elicitors.
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Palavras-chave
Óxido nítrico, Ácido hexanóico, Coffea arabica, Espécies reativas de oxigênio, Nitric oxide, Hexanoic acid, Reactive oxygen species