Memória fisiológica induz respostas fotoquímicas e bioquímicas em plantas de sorgo sob défice hídrico recorrente
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Data
2020-02-21
Autores
Leite, Lívia Carvalho
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O desenvolvimento das plantas é controlado por vários fatores ambientais dentre os quais a água, cujo papel vital determina o sucesso no estabelecimento vegetal. Embora as intervenções abióticas as quais estão sujeitas ao longo de seu desenvolvimento possam prejudicá-las, os eventos de estresse anteriores podem induzir seu metabolismo contra posteriores, influenciando respostas. Memória de estresse envolve múltiplas modificações em níveis fisiológicos, proteômicos, transcricionais e mecanismos epigenéticos em plantas em resposta às essas mudanças no ambiente. Neste estudo, sugeriu-se a hipótese de que as plantas de sorgo previamente expostas a ciclos de défice hídrico terão melhor desempenho fisiológico do que as que nunca enfrentaram esta condição, quando ambos grupos estão sujeitos à baixa disponibilidade de água. Este trabalho propôs identificar algumas das possíveis contribuições fisiológicas para com o desempenho fotoquímico de indivíduos da espécie Sorghum bicolor (L.) Moench submetidos a dois eventos de défice hídrico, em comparação com indivíduos expostos a apenas um evento, além do grupo controle mantido sob irrigação. As respostas fisiológicas observadas em plantas submetidas a défice hídrico recorrente indicam ajustes fisiológicos distintos das plantas do grupo submetido a esta condição apenas uma vez. Os resultados de relações hídricas, taxas fotossintéticas e conservação do aparato fotoquímico sugerem que experiência de estresse anterior pode desenvolver memória fisiológica. Os dados sugerem que as plantas foram capazes de armazenar informações do evento de restrição hídrica anterior, influenciando respostas durante o segundo evento de défice.
The development of plants is controlled by several environmental factors including water, whose vital role determines success in plant establishment. Notwithstanding the abiotic stresses that are subject throughout their development can harm them, stress events earlier tend to induce metabolism against further tensions in order to improve responses. Stress memory involves multiple changes in physiological, proteomic, transcriptional levels and epigenetic mechanisms in plants in response to these changes in the environment. In this study, the hypothesis was suggested that sorghum plants previously exposed to water deficit cycles will have a better physiological performance than those that never faced this condition, when both groups are subject to low water availability. This work proposed to identify some of the possible physiological contributions to the photochemical performance of individuals of the species Sorghum bicolor (L.) Moench submitted to two water deficit events, in comparison with individuals exposed to only one event, in addition to the control group kept under irrigation. The physiological responses observed in plants submitted to recurrent water deficit indicate physiological adjustments different from plants in the group submitted to this condition only once. The parameters of water relations, photosynthetic rates and conservation of the photochemical apparatus suggest that previous stress experience may develop physiological memory. The data suggest that the plants were able to store information from the previous water restriction event, as well as some changes during the acclimatization period improved responses during the second deficit event.
The development of plants is controlled by several environmental factors including water, whose vital role determines success in plant establishment. Notwithstanding the abiotic stresses that are subject throughout their development can harm them, stress events earlier tend to induce metabolism against further tensions in order to improve responses. Stress memory involves multiple changes in physiological, proteomic, transcriptional levels and epigenetic mechanisms in plants in response to these changes in the environment. In this study, the hypothesis was suggested that sorghum plants previously exposed to water deficit cycles will have a better physiological performance than those that never faced this condition, when both groups are subject to low water availability. This work proposed to identify some of the possible physiological contributions to the photochemical performance of individuals of the species Sorghum bicolor (L.) Moench submitted to two water deficit events, in comparison with individuals exposed to only one event, in addition to the control group kept under irrigation. The physiological responses observed in plants submitted to recurrent water deficit indicate physiological adjustments different from plants in the group submitted to this condition only once. The parameters of water relations, photosynthetic rates and conservation of the photochemical apparatus suggest that previous stress experience may develop physiological memory. The data suggest that the plants were able to store information from the previous water restriction event, as well as some changes during the acclimatization period improved responses during the second deficit event.
Descrição
Palavras-chave
Sorgo, Fotossíntese, Desidratação (Hídrica), Secas, Aclimatação (Plantas), Photosynthesis, Water stress, Acclimatization, Sorghum bicolor, Drought