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Knockdown of the A rabidopsis thaliana chloroplast protein disulfide isomerase 6 results in reduced levels of photoinhibition and increased D 1 synthesis in high light
Author(s) -
Wittenberg Gal,
Levitan Alexander,
Klein Tamir,
Dangoor Inbal,
Keren Nir,
Da Avihai
Publication year - 2014
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.12525
Subject(s) - chloroplast , photoinhibition , arabidopsis thaliana , protein disulfide isomerase , chemistry , disulfide bond , biochemistry , photosynthesis , photosystem ii , mutant , gene
Summary A chloroplast protein disulfide isomerase ( PDI ) was previously proposed to regulate translation of the unicellular green alga C hlamydomonas reinhardtii chloroplast psb A m RNA , encoding the D 1 protein, in response to light. Here we show that A t PDI 6, one of 13 A rabidopsis thaliana PDI genes, also plays a role in the chloroplast. We found that A t PDI 6 is targeted and localized to the chloroplast. Interestingly, A t PDI 6 knockdown plants displayed higher resistance to photoinhibition than wild‐type plants when exposed to a tenfold increase in light intensity. The A t PDI 6 knockdown plants also displayed a higher rate of D 1 synthesis under a similar light intensity. The increased resistance to photoinhibition may not be rationalized by changes in antenna or non‐photochemical quenching. Thus, the increased D 1 synthesis rate, which may result in a larger proportion of active D 1 under light stress, may led to the decrease in photoinhibition. These results suggest that, although the D 1 synthesis rates observed in wild‐type plants under high light intensities are elevated, repair can potentially occur faster. The findings implicate A t PDI 6 as an attenuator of D 1 synthesis, modulating photoinhibition in a light‐regulated manner.