Close relationship between the state of the oxygen evolving complex and rice cold stress tolerance

JUAN MANUEL VILAS; MARIANA CORIGLIANO; MARINA CLEMENTE; SANTIAGO JAVIER MAIALE; ANDRES ALBERTO RODRIGUEZ (CORRESPONDING AUTHOR)

PLANT SCIENCE

ELSEVIER IRELAND LTD

Año: 2020 vol. 296

0168-9452

The results of the present work suggested a relationship between the growth stability and functional/structuralparameters associated to the primary photochemistry and oxygen evolving complex (OEC) in tolerant rice plantsunder suboptimal low temperatures (SLT) stress. This was concluded from the absence of changes in net photosynthetic rate and in fraction of reaction centers to reduce quinone A, and very small changes in P680 efficiency to trap and donate electrons to quinone A and in fraction of active OEC in tolerant plants under cold stressbut not in sensitive plants. The SLT stress also induced OEC activity limitations in both genotypes, but in agreater extent in sensitive plants. However, an assay using an artificial electron donor to replace OEC indicatedthat the P680+ capacity to accept electrons was not altered in both genotypes under SLT stress from the beginning of the stress treatment, suggesting that the OEC structure stability is related to rice SLT tolerance tosustain the photosynthesis. This hypothesis was also supported by the fact that tolerant plants but not sensitiveplants did not alter the gene expression and protein content of PsbP under SLT stress, an OEC subunit with a rolein stabilizing of OEC structure.