Abstract
We focus on the leaf-variegated mutant var2 of Arabidopsis, to study the molecular mechanism leading to leaf variegation. We previously reported that the green sectors of the var2 variegated leaves accumulated high ROS under a normal growth condition. It was hypothesized that these ROS directly and/or indirectly play roles in an antibacterial activity. To test this hypothesis, we inoculated Pst DC3000 expressing GFP onto var2 leaves. At an early stage of inoculation, GFP was predominantly detected in white sectors but not in green sectors, likely due to the ROS accumulation in the green sectors. Bacterial counts in leaf extracts, based on the measurement of colonization, showed that var2 leaves were more tolerant to Pst DC3000 than the wild-type leaves. Thus, we present a possibility that although the mutation in var2 is defective in photosynthesis, the resulting ROS accumulation may be advantageous for a biotic stress.
