Plant Biotechnology Journal最新文献

Increasing the nutritional value of seed storage proteins (SSPs) has been largely hindered by limited knowledge of how the features of the various SSP domains determine high accumulation in protein storage vacuoles (PSV) or as endoplasmic reticulum (ER)-located insoluble protein bodies (PB). We had previously designed zeolin, a fusion between phaseolin (PHSL, the main bean SSP, a soluble trimeric protein located in PSV) and the N-terminal domain of 27 kDa γ-zein (27γz, a major maize PB prolamin). Zeolin has a more balanced essential amino acid composition than each parental sequence and forms insoluble homomeric PB very similar to natural maize heteropolymeric PB, indicating that the zein domain has a dominant effect over PHSL. We had also determined that the paralog 16 kDa γ-zein (16γz) remains partially soluble and forms unusual threads in the ER when ectopically expressed. We now produced zeolin2 (zeo2), by fusing PHSL to the N-terminal domain of 16γz. We show that only a minor proportion of zeo2 remains in the ER, without forming PBs or threads. Zeo2 mainly forms soluble trimers with biochemical characteristics very similar to PHSL trimers, and traffics to the vacuole via the Golgi complex. This indicates that the 16γz domain fails to significantly dominate over PHSL. In transgenic arabidopsis, zeo2 accumulates to markedly higher levels than phaseolin and only slightly lower levels than zeolin. Zeo2 is also more accessible than zeolin to proteases during the early stages of seed germination. These findings provide new information relevant for the design of modified, nutritionally enhanced storage proteins.

Microtubules (MTs) are crucial for cell division, growth, development and morphogenesis in plants. Cotton fibres are single-celled trichomes that originate from the epidermal cells of the ovule, making them an excellent model for studying plant cell differentiation and rapid elongation. However, the roles of MTs in cotton fibre development remain incompletely understood. In this study, we identified GhTTLL12, a tubulin-tyrosine ligase-like protein 12, as a positive regulator of fibre initiation and elongation via Gh-Gb introgression analysis. GhTTLL12 was preferentially expressed during the rapid elongation stage of cotton fibres. Overexpression of GhTTLL12 enhanced plant height, root length, fibre cell protrusion number and fibre length in cotton. Conversely, CRISPR/Cas9-mediated knockout of GhTTLL12 led to opposite phenotypes, thereby significantly reducing fibre quality. MT co-sedimentation and immunofluorescence assays demonstrated that GhTTLL12 binds directly to MTs and promotes their assembly while facilitating the formation of transverse MT arrays in elongating fibres. Further investigation of the molecular mechanisms revealed that after GhTTLL12 is recruited into the nucleus by GhTUB8, it promotes mitosis in ovule epidermal cells upon activation by GhMML3, increasing the number of fibre cell protrusions. GhMYB86, a negative regulator of cotton fibre elongation, represses GhTTLL12 transcription in the nucleus, leading to attenuated mitotic activity. Cytoplasmic GhTTLL12 modulates fibre cell elongation by regulating MT assembly and ordered arrangement. Collectively, our findings define a GhMML3/GhMYB86-GhTTLL12-GhTUB8 regulatory module that links stage-specific transcriptional regulation to MT remodelling during cotton fibre development, providing new insights into the improvement of fibre quality and yield.

To clarify how pectin heterogeneity relates to puree quality, this study investigated associations among pectin fractions, metabolite profiles, and physicochemical properties of peach purees from 20 cultivars with distinct viscosity, turbidity, and colour. Metabolomic analysis showed that sugars, organic acids, and phenolic compounds were closely associated with the yield of chelator-soluble pectin (CSP), indicating coordinated variation between metabolite profiles and structurally integrated pectin fractions across cultivars. CSP yield was further related to resistance to deformation, as reflected by yield stress. In contrast, rheological behaviour after yielding was more strongly associated with water-soluble pectin (WSP), whose yield and structural features were linked to viscosity, viscoelastic balance, and flow behaviour. Phenolic compounds such as taxifolin and phlorizin chalcone were associated with puree colour. Collectively, these results establish an applied evaluation framework linking metabolite variation, pectin fraction distribution, and cultivar-dependent quality traits. By connecting micro-biochemical compositions (metabolite profiles and pectin fractions) with macroscopic processing-related properties, this framework provides insights into cell wall-related characteristics relevant to peach puree quality and processing performance.

Sesame (Sesamum indicum L., 2n = 26) is one of the oldest oilseed crops and is often called the ‘queen of oilseeds’ due to its high content of unsaturated fatty acids and natural antioxidants. Despite its long history, the origin and global spread of cultivated sesame remain unresolved. We assembled a telomere-to-telomere (T2T), high-quality reference genome of sesame (cv. Yuzhi11) to investigate sequence differences between genomes and its origin and the local adaptation evolution of flowering time (DF). We generated a 305 Mb T2T sesame reference genome (cv. Yuzhi11) with > 99.99% base-level accuracy, identifying 31 063 protein-coding genes. Repetitive elements accounted for 52.03% of the genome. Population genomic analysis of 927 accessions from 14 regions identified four major groups. Integrative analyses of linkage disequilibrium decay (LD), nucleotide diversity (π), and fixation index (F_ST) support East Africa as the center of origin, with subsequent migration through the Middle East, to South Asia, South-East Asia, East Asia and ultimately to other parts of the world. Genome-wide association studies (GWAS) and selection scans identified 30 genes associated with flowering time. SiUBP16 is a candidate associated with 7.6% of DF variation. Early-flowering accessions carried up to 225 favourable alleles. A flowering time prediction model for high-latitude regions achieved 96% accuracy. We present a high-quality T2T reference genome for cultivated sesame, shedding light on its origin, evolutionary history, and regional flowering time adaptation. This genome insights valuable tools for breeding programs aimed at improving yield and environmental adaptation in sesame and related crops.

To ensure sustainable agricultural production under escalating environmental constraints such as drought and salinity, innovative strategies are urgently needed. Here, we reveal in foxtail millet (Setaria italica) that transcription factors TAF10 and ERF109 form a functional complex which co-activates the expression of key flavonoid biosynthesis genes (SiPAL, SiF3′H, SiFLS, SiF3H), thereby enhancing abiotic stress tolerance. Application of specific flavonoids (apigenin, naringenin, hesperetin) rescues stress-sensitive phenotypes in ERF109-RNAi and taf10 lines. Importantly, field-based application protocols for apigenin were established in both foxtail millet and wheat (Triticum aestivum), leading to yield increases of 12.3%–19.6% in wheat and 15.8%–23.9% in foxtail millet under drought and saline field conditions. Our study not only delineates a conserved transcriptional mechanism regulating flavonoid-mediated stress resilience but also delivers a translatable, eco-friendly biostimulant strategy to enhance crop productivity in stress-affected environments.

The single crossover occurring via homologous recombination is a common phenomenon existing among microbes like Escherichia coli, Bacillus subtilis, Vibrio natriegens, Gluconobacter oxydans and most cyanobacteria species, threatening the stability of engineered strains and challenging iterative genetic engineering. Among them, we take the fast-growing cyanobacterium Synechococcus elongatus UTEX 2973 (Syn2973) as a representative study due to its promising roles for CO₂ fixation and bioconversion. We established three marker-free platforms to achieve stable genome recombination: (i) T4CROSS, which employs two plasmids and four rounds of single crossover; (ii) TRIPLEARM, which uses a single plasmid containing three homologous arms for three rounds of single crossover; and (iii) CRISPRARM, which integrates CRISPR/Cpf1-mediated genome editing with homologous recombination. As proof of concept, we employed the CRISPRARM platform for a three-step sequential engineering of the sucrose biosynthetic pathway. The final engineered strain produced 7.12 g L⁻¹ of sucrose within 4 days.