Phosphatidylglycerol Composition Is Central to Chilling Damage in the Arabidopsis fab1 Mutant.
Plant Physiol
; 184(4): 1717-1730, 2020 12.
Article
em En
| MEDLINE
| ID: mdl-33028639
ABSTRACT
The Arabidopsis (Arabidopsis thaliana) fatty acid biosynthesis1 (fab1) mutant has increased levels of the saturated fatty acid 160, resulting from decreased activity of 3-ketoacyl-ACP synthase II. In fab1 leaves, phosphatidylglycerol, the major chloroplast phospholipid, contains >40% high-melting-point molecular species (HMP-PG; molecules that contain only 160, 161-trans, and 180 fatty acids)-a trait associated with chilling-sensitive plants-compared with <10% in wild-type Arabidopsis. Although they do not exhibit short-term chilling sensitivity when exposed to low temperatures (2°C to 6°C) for long periods, fab1 plants do suffer collapse of photosynthesis, degradation of chloroplasts, and eventually death. To test the relevance of HMP-PG to the fab1 phenotype, we used transgenic 160 desaturases targeted to the endoplasmic reticulum and the chloroplast to lower 160 in leaf lipids of fab1 plants. We produced two lines that had very similar lipid compositions except that one, ER-FAT5, contained high HMP-PG, similar to the fab1 parent, while the second, TP-DES9*, contained <10% HMP-PG, similar to the wild type. TP-DES9* plants, but not ER-FAT5 plants, showed strong recovery and growth following 75 d at 2°C, demonstrating the role of HMP-PG in low-temperature damage and death in fab1, and in chilling-sensitive plants more broadly.
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Base de dados:
MEDLINE
Assunto principal:
Fosfatidilgliceróis
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Cloroplastos
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Arabidopsis
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Temperatura Baixa
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Proteínas de Arabidopsis
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Ácidos Graxos
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Aclimatação
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article