Modificações bioquímicas e moleculares ajustam o uso da energia da luz em plantas de Guzmania monostachia induzidas ao CAM por deficiência hídrica

Abstract

Photosynthesis is a light-energy absorption process that results in NADPH and ATP production, which can be used to assimilate CO2 and produce carbohydrates. Stress conditions can decrease the photosynthetic rate due to stomatal closure limiting the atmospheric carbon assimilation and downregulating the capacity of light absorption. Epiphytic plants normally do not have access to CO2 uptake was null in water deficit plants. In addition, the results showed an upregulation, especially at 12:00h, of kinases transcript levels responsible for thylakoid protein phosphorylation. The increase in the phosphorylation of these proteins can induce changes in the thylakoid membrane conformation, which facilitates the linear electron transport, consequently powering the CO2 assimilation in CAM plants, particularly at the time with the major availability of this gas. The results also indicated a reduction in PSII/PSI protein proportion after 20 days of drought. As a result, the CAM induction appears to be followed by biochemical and molecular modulations adjusting the light-energy absorption and use, which could facilitate the survival of this species under stressful conditions.