Differential response of the photosynthetic machinery to dehydration in older and younger resurrection plants.
J Exp Bot
; 73(5): 1566-1580, 2022 03 02.
Article
em En
| MEDLINE
| ID: mdl-34747457
ABSTRACT
A group of vascular plants called homoiochlorophyllous resurrection plants evolved unique capabilities to protect their photosynthetic machinery against desiccation-induced damage. This study examined whether the ontogenetic status of the resurrection plant Craterostigma pumilum has an impact on how the plant responds to dehydration at the thylakoid membrane level to prepare cells for the desiccated state. Thus, younger plants (<4 months) were compared with their older (>6 months) counterparts. Ultrastructural analysis provided evidence that younger plants suppressed senescence-like programs that are realized in older plants. During dehydration, older plants degrade specific subunits of the photosynthetic apparatus such as the D1 subunit of PSII and subunits of the cytochrome b6f complex. The latter leads to a controlled down-regulation of linear electron transport. In contrast, younger plants increased photoprotective high-energy quenching mechanisms and maintained a high capability to replace damaged D1 subunits. It follows that depending on the ontogenetic state, either more degradation-based or more photoprotective mechanisms are employed during dehydration of Craterostigma pumilum.
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Base de dados:
MEDLINE
Assunto principal:
Fotossíntese
/
Craterostigma
Idioma:
En
Ano de publicação:
2022
Tipo de documento:
Article