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Thousand-grain weight (TGW) of wheat (Triticum aestivum L.) contributes significantly to grain yield. In the present study, a candidate gene associated with TGW was identified through specific-locus amplified fragment sequencing (SLAF-seq) of DNA bulks of recombinant inbred lines (RIL) derived from the cross between Jing 411 and Hongmangchun 21. The gene was located on chromosome 7A, designated as TaTGW-7A with a complete genome sequence and an open reading frame (ORF). A single nucleotide polymorphism (SNP) was present in the first exon between two alleles at TaTGW-7A locus, resulting in a Val to Ala substitution, corresponding to a change from higher to lower TGW. Cleaved amplified polymorphic sequence (CAPS) (TGW7A) and InDel (TG9) markers were developed to discriminate the two alleles TaTGW-7Aa and TaTGW-7Ab for higher and lower TGW, respectively. A major QTL co-segregating with TaTGW-7A explained 21.7–27.1% of phenotypic variance for TGW in the RIL population across five environments. The association of TaTGW-7A with TGW was further validated in a natural population and Chinese mini-core collections. Quantitative real-time PCR revealed higher transcript levels of TaTGW-7Aa than those of TaTGW-7Ab during grain development. High frequencies of the superior allele TaTGW-7Aa for higher TGW in Chinese mini-core collections (65.0%) and 501 wheat varieties (86.0%) indicated a strong and positive selection of this allele in wheat breeding. The molecular markers TGW7A and TG9 can be used for improvement of TGW in breeding programs.

Maize kernel weight is influenced by the unloading of nutrients from the maternal placenta and their passage through the transfer tissue of the basal endosperm transfer layer (BETL) and the basal intermediate zone (BIZ) to the upper part of the endosperm.Here, we show that Small kernel 10 (Smk10) encodes a choline transporter-like protein 1 (ZmCTLP1) that facilitates choline uptake and is located in the trans-Golgi network (TGN). Its loss of function results in reduced choline content, leading to smaller kernels with a lower starch content.Mutation of ZmCTLP1 disrupts membrane lipid homeostasis and the normal development of wall in-growths. Expression levels of Mn1 and ZmSWEET4c, two kernel filling-related genes, are downregulated in the smk10, which is likely to be one of the major causes of incompletely differentiated transfer cells. Mutation of ZmCTLP1 also reduces the number of plasmodesmata (PD) in transfer cells, indicating that the smk10 mutant is impaired in PD formation. Intriguingly, we also observed premature cell death in the BETL and BIZ of the smk10 mutant.Together, our results suggest that ZmCTLP1-mediated choline transport affects kernel development, highlighting its important role in lipid homeostasis, wall in-growth formation and PD development in transfer cells.

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Anther development from stamen primordium to pollen dispersal is complex and essential to sexual reproduction. How this highly dynamic and complex developmental process is controlled genetically is not well understood, especially for genes involved in specific key developmental phases. Here we generated RNA sequencing libraries spanning 10 key stages across the entirety of anther development in maize (Zea mays). Global transcriptome analyses revealed distinct phases of cell division and expansion, meiosis,