Genotype-dependent differences in S12-RNase expression lead to sporadic self-compatibility.

Area of Science:

• Plant reproductive biology
• Molecular genetics
• Solanum genetics

Background:

• Sporadic self-compatibility, occasional fruit set in incompatible pollinations, is observed in some Solanum chacoense genotypes with the S12 allele.
• S-RNase levels and their regulation are critical for self-incompatibility mechanisms in Solanum species.

Purpose of the Study:

• To investigate the molecular basis of variable self-compatibility in Solanum chacoense.
• To analyze the expression and modification of the S12-RNase allele across different genotypes.

Main Methods:

• Sequencing of the S12 allele.
• Analysis of S12-RNase and S12 RNA expression levels in four Solanum chacoense genotypes.
• Investigation of protein glycosylation patterns.

Main Results:

• S12-RNase levels were generally lower than other S-RNases and varied significantly among genotypes.
• Genotypes with higher S12-RNase levels exhibited strong self-incompatibility, while lower levels correlated with sporadic self-compatibility.
• Genotype-specific differences in S12-RNase glycosylation were observed.

Conclusions:

• Modifier genes likely regulate S12-RNase expression levels and post-translational modifications in a genotype-dependent manner.
• These regulatory mechanisms contribute to the observed variation in self-compatibility within Solanum chacoense.