Phenotypic Analysis and Gene Cloning of Rice Floury Endosperm Mutant wcr (White-Core Rice).

Area of Science:

• Plant genetics
• Molecular biology
• Biochemistry

Background:

• Grain quality in rice is determined by the composition and distribution of storage substances in the endosperm.
• A floury endosperm mutant, white-core rice (wcr), displays altered grain characteristics.

Purpose of the Study:

• To investigate the genetic basis and molecular mechanisms underlying the wcr mutant phenotype.
• To understand the role of the affected gene in rice grain development and quality.

Main Methods:

• Gene mapping to identify the mutated gene.
• Mutation analysis to characterize the genetic alteration.
• Gene expression analysis to study regulatory effects on metabolic pathways.

Main Results:

• The wcr mutation, caused by a frameshift in the cyOsPPDKB gene, leads to a floury endosperm with reduced grain weight.
• Mutant rice shows altered starch properties (reduced swelling, changed chain length) and decreased storage protein content, with increased albumin in milled rice.
• The wcr mutation affects genes involved in both starch metabolism and storage protein synthesis.

Conclusions:

• The cyOsPPDKB gene is essential for regulating starch metabolism and protein synthesis in rice grains.
• The wcr mutation provides insights into the genetic control of rice endosperm development and grain quality.