Myo-inositol oxygenase CgMIOX3 alleviates S-RNase-induced inhibition of incompatible pollen tubes in pummelo.
Plant Physiol
; 196(2): 856-869, 2024 Oct 01.
Article
em En
| MEDLINE
| ID: mdl-38991562
ABSTRACT
Pummelo (Citrus grandis L. Osbeck) exhibits S-RNase-based self-incompatibility (SI), during which S-RNase cytotoxicity inhibits pollen tubes in an S-haplotype-specific manner. The entry of S-RNase into self-pollen tubes triggers a series of reactions. However, these reactions are still poorly understood in pummelo. In the present study, we used S-RNases as baits to screen a pummelo pollen cDNA library and characterized a myo-inositol oxygenase (CgMIOX3) that physically interacts with S-RNases. CgMIOX3 is highly expressed in pummelo pollen tubes, and its downregulation leads to a reduction in pollen tube growth. Upon entering pollen tubes, S-RNases increase the expression of CgMIOX3 and enhance its activity by directly binding to it in an S-haplotype-independent manner. CgMIOX3 improves pollen tube growth under oxidative stress through ascorbic acid (AsA) accumulation and increases the length of self-pollen tubes. Furthermore, over-expression of CgMIOX3 increases the relative length of self-pollen tubes growing in the style of petunia (Petunia hybrida). This study provides intriguing insights into the pumelo SI system, revealing a regulatory mechanism mediated by CgMIOX3 that plays an important role in the resistance of pollen tubes to S-RNase cytotoxicity.
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Base de dados:
MEDLINE
Assunto principal:
Proteínas de Plantas
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Citrus
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Regulação da Expressão Gênica de Plantas
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Inositol Oxigenase
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Tubo Polínico
Idioma:
En
Ano de publicação:
2024
Tipo de documento:
Article