Photosynthetic behaviour of Arabidopsis plants with a Cap Binding Protein 20 mutation under water stress

Abstract

Under non-stressed conditions the net photosynthetic rate (P N ) of the mutant plants cbp20 of Arabidopsis was similar to that of the wild type (WT). In response to water deprivation, however, P N started to decrease later in the mutants and remained substantially higher. Thermoluminescence measurements showed that the lipid peroxidation induced by severe water stress was also less pronounced in the mutant than in the WT. Both soil gravimetric and plant water potential data showed that cbp20 mutants lose water more slowly than the WT plants. The drought-induced decline in F v /F m , the quantum efficiency of photosystem 2, and photochemical quenching parameters also started later in the cbp20 mutants than in the WT plants. Thus the restricted gas exchange in the cbp20 mutants does not impair the photosynthetic performance of the plant; however, under drought improved water retention provides significant protection for the photosynthetic apparatus.

New phenotypes of the drought‐tolerant cbp20 Arabidopsis thaliana mutant have changed epidermal morphology

“…In summary some of the new morphological features described above may help to explain the water-saving characteristics of the cbp20 mutant (Papp et al 2004;Bacsó et al 2008b). Changes in development may thus contribute to the already described dynamic features that prevent desiccation in the nCBC class of mutant under drought stress.…”

“…In summary some of the new morphological features described above may help to explain the water‐saving characteristics of the cbp20 mutant (Papp et al. 2004; Bacsó et al. 2008b).…”

“…2004). Water saving by restricted gas exchange does not necessarily hinder photosynthesis, and thus may prove beneficial in water‐limited environments (Bacsó et al. 2008b).…”

Atnoa1 mutant Arabidopsis plants induce compensation mechanisms to reduce the negative effects of the mutation

“…When photoinhibition is a determining component of the stress response, as earlier demonstrated for example, under chilling conditions, F v /F m may rapidly decrease (Janda et al, 1994). In other cases, such as drought stress, F v /F m was only reduced by severe stress (Németh et al, 2002;Bacsó et al, 2008;Petsas and Grammatikopoulos, 2009). In the case of the Atnoa1 mutant, both F o and F m were higher than in the wildtype; however, the increase in F o , probably due to the dissociation of the light harvesting system of PS 2 from the PS 2 core complex, was more pronounced than that in F m , which led to a drop in F v /F m .…”