BnaC9.SMG7b Functions as a Positive Regulator of the Number of Seeds per Silique in Brassica napus by Regulating the Formation of Functional Female Gametophytes.
BnaC9.SMG7b plays a role in regulating the formation of functional female gametophyte, thus determining the formation of functional megaspores and then mature ovules.
Haplotype analysis in 84 accessions showed that the favorable BnaC9.SMG7b alleles are prevalent in modern B. napus germplasms, suggesting that this locus has been a major selection target of B. napus improvement.
Natural loss or artificial knockdown of BnaC9.SMG7b significantly reduces the number of functional ovules per silique and thus, results in decreased seed number, indicating that qSS.C9 is a positive regulator of NSS in B. napus. Sequence and function analyses show that BnaC9.SMG7b experiences a subfunctionalization process that causes loss of function in nonsense-mediated mRNA decay, such as in Arabidopsis SMG7.
