Pathogen-induced changes in malate content and NADP-dependent malic enzyme activity in C3 or CAM performing Mesembryanthemum crystallinum L. plants

Abstract

Changes in malate concentration and activity of NADP-dependent malic enzyme were observed as the effect of Botrytis cinerea infection of C 3 or CAM-performing Mesembryanthemum crystallinum plants. Biotic stress applied on C 3 plants led to increase in malate concentration during the night and in consequence it led to increase in D-malate (day/night fluctuations) in infected leaves on the 2nd day post infection (dpi). It corresponded with induction of additional isoform of NADP-malic enzyme (NADP-ME3). On the contrary, CAM-performing M. crystallinum plants exhibited decrease in malate concentration and decay in its diurnal fluctuations as a reaction to B. cinerea infection. This correlated with significant decrease in activities of NADP-malic enzyme isoforms on the 2nd dpi as well as no fluctuations in their activities on the 9th dpi. Presented results point out to differences between C 3 and CAM plants in the direction of changes in primary metabolism providing energy, reducing equivalents and carbon skeletons for defense responses to halt the pathogen growth.

Transcription Factor McHB7 Improves Ice Plant Drought Tolerance through ABA Signaling Pathway

“…A possible explanation for these results is that an enhanced enzymatic antioxidant system may exist in the OE leaves to maintain redox homeostasis. Moreover, ROS may be part of the transition from C 3 to CAM, as CAM acts as an important component in reducing the oxidative damage caused by stress [28,43]. In particular, H 2 O 2 is reported to be a signaling molecule participating in cellular responses like promoting stress-related protein production and increasing antioxidant molecules [44].…”

Proteomic analysis of gametophytic sex expression in the fern Ceratopteris thalictroides

“…DHAR, a type of glutathione S-transferase, can catalyse the synthesis of ascorbic acid by dehydroascorbate, which is a cofactor in the xanthophyll cycle and a highly effective antioxidant that helps plants excrete reactive oxygen [37]. Malate dehydrogenase might provide building material and energy for the biosynthesis of defence compounds [38]. Arginase 1 has been shown to mobilize nitrogen storage as well as fine-tune development and defence mechanisms against stress [39].…”