BnaC9.SMG7b functions as a positive regulator of number of seeds per silique in rapeseed (Brassica napus L.) by regulating the formation of functional female gametophytes

Li, S; Chen, L; Zhang, L; Li, X; Liu, Y; Wu, Z; Dong, F; Wan, L; Liu, K; Hong, D; Yang, G

HERO ID

3044614

Reference Type

Journal Article

Year

2015

Language

English

PMID

26494121

HERO ID 3044614
In Press No
Year 2015
Title BnaC9.SMG7b functions as a positive regulator of number of seeds per silique in rapeseed (Brassica napus L.) by regulating the formation of functional female gametophytes
Authors Li, S; Chen, L; Zhang, L; Li, X; Liu, Y; Wu, Z; Dong, F; Wan, L; Liu, K; Hong, D; Yang, G
Journal Plant Physiology
Abstract Number of seeds per silique (NSS) is an important determinant of seed yield potential in Brassicaceae crops and is controlled by naturally occurring quantitative trait loci (QTLs). We previously mapped a major QTL, qSS.C9, on the C9 chromosome that controls NSS in rapeseed (Brassica napus L.). To gain a better understanding of how qSS.C9 controls NSS in rapeseed, we isolated this locus through a map-based cloning strategy. qSS.C9 encodes a predicted small protein with 119 amino acids, designated as BnaC9.SMG7b, that shows homology with the Ever Shorter Telomere 1-tertratricopeptide repeats (EST-TPR) and EST-central domains (CD) of Arabidopsis SUPPRESSOR WITH MORPHOGENETIC EFFECTS ON GENITALIA7 (SMG7). BnaC9.SMG7b plays a role in regulating the formation of functional female gametophyte, thus determining the formation of functional megaspores and then mature ovules. 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 (NMD), as in Arabidopsis SMG7. 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. Our results represent the first step toward unraveling the molecular mechanism that controls the natural variation of NSS in rapeseed.
Doi 10.1104/pp.15.01040
Pmid 26494121
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Dupe Override No
Is Public Yes
Language Text English