O balanço entre o desenvolvimento estrutural e o fisiológico de folhas de Eugenia uniflora (Myrtaceae) com distintos níveis de maturação

Abstract

The luminosity that reaches the plants vary according to the type of ecosystem that these individuals are inserted, affecting both directly and indirectly the development, energy production etc. The amount and quality of solar rays may trigger physiological processes such as oxidative stress, which can be harmful to the plant, as well as photoprotective pigments (anthocyanins and carotenoids). The objective of this work was to evaluate if young, transitional and mature leaves of Eugenia uniflora (Myrtaceae) with different levels of maturation would have modifications in the physiological and structural traits of their leaf tissues. During the foliar maturation, the 2nd and 4th nodes complete their elongation and development, consequently increasing the content of photosynthetic pigments, as well as the concentration of ROS in specific tissues. The reddish coloration in young leaves of E. uniflora is due to the greater accumulation of photoprotective pigments, homogenizing the distribution of light leading to the lower production of malonaldehyde in the initial stages of development. In the end, leaf maturity and less structural light scaling did not lead to increased photoinhibition or reduction of quantum yield, causing only a lower efficiency in electron transport.