Caracterização sistêmica de alterações em redes fisiológicas de plantas C3 e C4 submetidas à deficiência hídrica
Data
2012-02-29
Autores
Bertolli, Suzana Chiari [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
O objetivo geral foi o de investigar o fenômeno da homeostase em plantas cultivadas de metabolismo C3 e C4 submetidas à deficiência hídrica, utilizando para isto a abordagem do “Paradigma Sistêmico”. Tal abordagem permite a superação de certas limitações impostas pela abordagem cartesiana clássica, levando a uma nova interpretação de fenômenos fisiológicos com a possibilidade de desvendar mecanismos de controle subjacentes às respostas das plantas submetidas à perturbações ambientais potencialmente estressantes. A partir dos conceitos de homeostase, plasticidade fenotípica e estabilidade do desenvolvimento, o dissertação foi desenvolvida em torno de um experimento envolvendo condições de maior e menor variabilidade ambiental, isto é, em ambiente controlado e semi-controlado. Foram utilizadas como espécies-modelo nesse estudo a soja (Glycine max), de metabolismo C3, e o capim marandú (B. brizantha brizantha), de metabolismo C4, permitindo maior generalização dos resultados entre espécies cultivadas herbáceas. Diferentes aspectos fisiológicos foram considerados na análise das respostas das plantas submetidas aos diferentes regimes hídricos e ambientes de crescimento, como produção de biomassa, e fotossíntese, todos integrados em uma rede de relações. De forma geral, os resultados indicaram que apesar de as duas espécies serem de metabolismos fotossintéticos diferentes, não apresentaram diferenças claras nas suas respostas a todas as condições testadas, mostrando desempenhos fisiológicos e plasticidade fenotípica relativamente similares. As diferenças entre os resultados das análises de conectância global (Cg) indicam que o padrão de modulação das redes fisiológicas em resposta à deficiência hídrica pode ser espécie-específico e dependente da condição de crescimento (variabilidade ambiental)
The general aim of this study was to investigate the phenomenon of homeostasis in plants of metabolism C3 and C4 under water deficit, using the approach of systemic paradigm. This approach helps to overcome limitations imposed by classical Cartesian approach, leading to a new interpretation of physiological phenomena with the possibility to unravel the control mechanisms underlying plant responses subjected to potentially stressful environmental disturbances. Based on the concepts of homeostasis, phenotypic plasticity and developmental stability, the project was developed around an experiment in conditions of high and low environmental variability, in other words, in a controlled and semi-controlled environment. Were used two species in this study, soybean (Glycine max), C3 metabolism, and Marandu grass (Brachiaria brizantha), C4 metabolism, allowing greater generalization of results between cultivated herbs species. Different physiological aspects were considered in the analysis of plant responses under different water regimes and growth environments, such as biomass and photosynthesis, all integrated into a network of relationships. Overall, the results indicated that although both species being different photosynthetic metabolisms, they showed no clear differences in their responses to all conditions tested, showing relatively similar response of phenotypic plasticity and physiological performance. The differences between the results of the global connectance (Cg) indicate that the modulation pattern of physiological networks in response to water deficit may be species-specific and dependent on the growth condition (environmental variability)
The general aim of this study was to investigate the phenomenon of homeostasis in plants of metabolism C3 and C4 under water deficit, using the approach of systemic paradigm. This approach helps to overcome limitations imposed by classical Cartesian approach, leading to a new interpretation of physiological phenomena with the possibility to unravel the control mechanisms underlying plant responses subjected to potentially stressful environmental disturbances. Based on the concepts of homeostasis, phenotypic plasticity and developmental stability, the project was developed around an experiment in conditions of high and low environmental variability, in other words, in a controlled and semi-controlled environment. Were used two species in this study, soybean (Glycine max), C3 metabolism, and Marandu grass (Brachiaria brizantha), C4 metabolism, allowing greater generalization of results between cultivated herbs species. Different physiological aspects were considered in the analysis of plant responses under different water regimes and growth environments, such as biomass and photosynthesis, all integrated into a network of relationships. Overall, the results indicated that although both species being different photosynthetic metabolisms, they showed no clear differences in their responses to all conditions tested, showing relatively similar response of phenotypic plasticity and physiological performance. The differences between the results of the global connectance (Cg) indicate that the modulation pattern of physiological networks in response to water deficit may be species-specific and dependent on the growth condition (environmental variability)
Descrição
Palavras-chave
Fisiologia vegetal, Homeostase, Plantas - Metabolismo, Plantas - Efeito da seca, Plantas - Adaptação
Como citar
BERTOLLI, Suzana Chiari. Caracterização sistêmica de alterações em redes fisiológicas de plantas C3 e C4 submetidas à deficiência hídrica. 2012. 85 f. Dissertação - (mestrado) - Universidade Estadual Paulista, Instituto de Biociências de Rio Claro, 2012.