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Yanyan Li

Publications and source records attributed to Yanyan Li.

3 recordsLinked to original sources

Genome-wide characterization of BraABCB transporters reveals their potential roles in hormone responses in Brassica rapa var. parachinensis.

Thirty-six BraABCB genes were identified in Brassica rapa var. parachinensis; expression and interaction analyses suggest BraABCB27 and BraABCB28 as hormone-responsive candidates associated with BRI1-related proteins. ABCB transporters are ATP-dependent membrane proteins that mediate the transport of diverse substrates, including phytohormones, and play important roles in plant development and environmental adaptation. Previous studies in Arabidopsis have shown that several ABCB proteins participate in phytohormone transport, including auxin and brassinosteroid transport, whereas the functions of their homologs in Brassica rapa var. parachinensis remain poorly understood. In this study, 36 BraABCB genes were identified and classified into four phylogenetic groups. Conserved domain analysis showed that BraABCB proteins contain typical nucleotide-binding domains and transmembrane domains. Chromosomal distribution, collinearity, and Ka/Ks analyses suggested that the BraABCB family is evolutionarily conserved and mainly subject to purifying constraints. Promoter analysis and RT-qPCR assays of selected Group IV BraABCB genes revealed diverse expression patterns and responses to drought, high temperature, brassinolide, and indole-3-acetic acid treatments. Subcellular localization assays showed that selected Group IV BraABCB proteins exhibited predominant plasma membrane localization. Notably, BraABCB27 and BraABCB28, two close AtABCB1/AtABCB19-related homologs, showed detectable physical associations with BRI1-related proteins in BiFC and split-ubiquitin yeast two-hybrid assays. Together, these results provide a genome-wide characterization of the BraABCB gene family and identify BraABCB27 and BraABCB28 as candidate genes for future studies of their possible associations with BR-related membrane processes and hormone-regulated growth responses in B. rapa var. parachinensis.

Plant Growth Regulators

Wheat breeding during and after the "green revolution" contributed to the reduced use of elite nitrogen metabolism alleles linked to nitrogen use efficiency.

The wheat "Green Revolution (GR)" that occurred from the 1960s to the 1970s significantly enhanced the harvest index and resistance to lodging, thereby increasing grain production, but at the cost of reduced nitrogen (N) use efficiency (NUE) in wheat. The NUE of wheat is mainly regulated by N metabolism genes (NMGs). However, the evolutionary process of NMGs during GR and post-GR wheat breeding, as well as which of them affect NUE, remains unclear. Here, we collected 265 wheat varieties that were released before, during, and after the GR and investigated grain yield per plant and 24 other traits under different N supply conditions. Next, we identified the genotypes of these wheat varieties using a 100 K targeted sequencing array. Then, we systematically analyzed the signatures in the genomes of GR and post-GR released varieties compared with pre-GR released varieties through population divergence (Fst) and nucleotide diversity (π) ratio analyses, and found that 41 NMGs were located within the selective sweep regions during the GR and post-GR breeding. We further identified 118 quantitative trait loci (QTLs) involved in regulating NUE through genome-wide association studies (GWAS). Four NMGs-NRT1 AND PEPTIDE TRANSPORTER FAMILY 2.7-D (TaNPF2.7-D), TaNPF2.3-D, TaNPF2.7 L-D, and QUASIMODO2-B (TaQUA2-B)-were located within overlapping regions of selective sweeps and NUE-related QTLs. Notably, the elite haplotypes of these genes for NUE are less utilized in GR and post-GR released cultivars. Furthermore, we found that TaNPF2.7-D positively regulates nitrate exudation as well as the wheat development. Collectively, our findings uncover an important reason for the reduction in NUE in modern cultivars and provide a valuable resource for improving wheat NUE.

Triticum

Selection of GhTT2-A07 promoter enhances fiber quality in improved cotton varieties.

Modern cultivated cotton fibers are predominantly white with enhanced quality compared to their wild ancestors. However, the molecular mechanisms and evolutionary drivers linking fiber color to quality remain least focused. In this study, we identified FQC1 (Fiber Quality and Color 1), a major quantitative trait locus (QTL) on chromosome A07 that concurrently regulates both fiber quality and pigmentation. Through map-based cloning, we revealed that Gossypium hirsutum TRANSPARENT TESTA2-A07 (GhTT2-A07), an R2R3-MYB transcription factor, resides within this locus. GhTT2-A07 modulates fiber development by directly activating genes in the general phenylpropanoid pathway, thereby promoting the metabolic flux toward downstream secondary metabolites. Variations in the GhTT2-A07 promoter led to its reduced expression in modern white cotton cultivars. This down-regulation suppresses the accumulation of S/G/H-type lignin monomers and proanthocyanidins, resulting in altered secondary cell wall composition and ultimately enhancing the quality of mature white fibers. Population genetic analyses further indicate that the white-fiber allele GhTT2-A07W has been fixed in modern breeding genotypes, underscoring the impact of artificial selection during cotton domestication. Overall, our study elucidates the biochemical and molecular mechanisms underlying fiber quality and pigmentation in cotton, clarifies the selection criteria for high-quality white fibers in modern cultivars, and provides a theoretical basis for future targeted genetic improvement of cotton fibers.

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