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

Lugar: Amsterdam; Año: 2020 vol. 296

0168-9452

The results of the present work suggested arelationship between the growth stability and functional/structural parametersassociated to the primary photochemistry and oxygen evolving complex (OEC) intolerant rice plants under suboptimal low temperatures (SLT) stress. This wasconcluded from the absence of changes in net photosynthetic rate and infraction of reaction centers to reduce quinone A, and very small changes inP680 efficiency to trap and donate electrons to quinone A and in fraction ofactive OEC in tolerant plants under cold stress but not in sensitive plants. The SLT stress also induced OEC activity limitations inboth genotypes, but in a greater extent in sensitive plants. However, an assayusing an artificial electron donor to replace OEC indicated that the P680+capacity to accept electrons was not altered in both genotypes under SLT stressfrom the beginning of the stress treatment, suggesting thatthe OEC structure stability is related to rice SLT tolerance to sustain thephotosynthesis. This hypothesis was also supported by the fact that tolerantplants but not sensitive plants did not alter the gene expression and proteincontent of PsbP under SLT stress, an OEC subunit with a role in stabilizing of OECstructure.