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[学术文献 ] Enhancing melatonin biosynthesis in crops through synthetic genetic circuits: A strategy for nutritional fortification in soybean and stress resistance in cotton 进入全文
PLANT BIOTECHNOLOGY JOURNAL
Melatonin has gained considerable prominence in the treatment of insomnia that significantly impacts one-third of the global population. The production of melatonin remains challenging due to limitations in current methods. Thus, there is an urgent need for developing more efficient and innovative production techniques. Here, we demonstrated the potential of crop seeds as a platform for melatonin synthesis by engineering multiple BUFFER genetic circuits using synthesized transcriptional regulators, which enhance expression precision, orthogonality and thresholds. Biofortified soybeans exhibited a 31-fold increase in melatonin content compared to standard Williams 82, without detrimental impact on yield. Protein content was elevated, oil content reduced and the soybeans were suitable for post-harvest processing. Furthermore, plants enriched in endogenous melatonin exhibited stronger resilience to adversity, evidenced by improved salinity tolerance in soybean seeds and increased resistance to Verticillium dahliae in cotton. Our research paves the way for the synthesis of target compounds in staple crops using synthetic genetic circuits, facilitating the development of novel biofortified crops to increase nutritional availability and environmental adaptability in the upcoming new era of agriculture.
[前沿资讯 ] 华中农大团队通过代谢组学和细胞壁多糖组学解析纤维长度的调控模型 进入全文
生物通
棉花纤维作为一种重要的天然纤维，是纺织工业的主要原料。棉纤维的胞内和细胞壁的代谢物会影响纤维细胞伸长和细胞壁的合成过程，对成熟纤维长度有重要作用，然而纤维内代谢物的遗传机制及对成熟纤维长度的影响尚不清楚。 近日，我校棉花遗传改良团队在杂志New Phytologist发表题为“Identification of genetic basis underlying mature cotton fiber length through metabolite-based genome wide association analysis”的研究论文。该研究通过对251份棉花自然群体的15DPA纤维进行非靶向代谢物测定以及20DPA纤维进行细胞壁多糖测定，结合群体重测序及表达谱数据，鉴定出一系列可用于改善棉纤维长度的遗传位点，提出一个新的成熟纤维长度的遗传代谢调控模型。 该团队使用液相色谱-串联质谱方法（liquid chromatography-tandem mass spectrometry ，LC-MS/MS）对251份棉花自然群体进行代谢谱分析，对15DPA棉纤维的代谢产物进行了表征。代谢数据分析鉴定出857种代谢物，对各类代谢产物的变异系数（CV, %）进行分析，约16%的代谢产物的CV大于50%。广义遗传力（H2）分析发现，有超过65%的代谢产物的H2大于0.5。这表明代谢产物可以为群体遗传研究的性状。此外通过Pearson相关分析，对这些代谢物进行了特征分析。 此前，课题组基于群体的基因组信息，建立了包含2,372,767个SNP的数据集。采用线性混合模型对857个代谢产物进行了mGWAS。初步鉴定到 A06的热点区域（75~100Mb）与15DPA的代谢产物显著相关，并具有最密集的mQTL。显著SNPs的分布表明，大多数代谢物（主要注释为寡肽、AA和AA衍生物）与染色体A06中85 - 96.2 Mb的SNPs相关。连锁不平衡（LD）分析显示，该区域的SNPs具有很强的连锁效应。结合单倍型分析，Hap2和Hap3棉花种质中积累的代谢物更多。此外，比较3种单倍型间成熟纤维性状的差异，纤维长度、皮棉百分比和纤维长度均匀度的差异较大， 确定Hap3是纤维表型更佳的优良单倍型。 最显著的SNPs位于block1 （85.09 ~ 90.22 Mb）和block4 (93.75 ~ 96.18 Mb)，这两个位点是可能性最大的候选区间。对此区间的候选基因的表达模式、单倍型间的表型差异、以及种质间的表达量差异进行分析，确定了两个候选基因Ghir_A06G013480和Ghir_A06G014150。 通过与mQTL有关联的193个代谢物与棉花群体成熟纤维性状进行Pearson相关分析。大部分代谢物（101/193）与纤维长度、皮棉百分比和长度均匀度呈强正相关。对与101个代谢物显著相关的基因进行GO富集分析，发现主要富集在植物细胞壁生物发生、角质层发育、脂质代谢和超长链脂肪酸代谢通路中。 基于GC-MS的方法，对群体的20DPA棉纤维样品进行定量细胞壁多糖组分析，共鉴定出10种多糖成分。15DPA代谢物与20DPA细胞壁多糖之间的相关性分析表明，大多数代谢物与纤维素呈负相关；结合单倍型分析，qA06:85-96.2Mb位点的Hap3基因型种质积累了更少的纤维素，但其纤维长度等品质更好，表明纤维伸长到次生壁加厚的转换期过多纤维素积累会对成熟纤维性状产生负面影响。 对纤维细胞壁多糖组分进行GWAS分析，鉴定到多个显著的QTL位点。其中8种成分：鼠李糖半乳糖醛酸（Rhamnogalacturonan）, 阿拉伯聚糖（Arabinan）, I型阿拉伯半乳聚糖（I-Arabinogalactan），II 型阿拉伯半乳聚糖（II-Arabinogalactan），异质木聚糖（Heteroxylan），异质甘露聚糖（Heteromannan），木葡聚糖（Xyloglucan）和纤维素（Cellulose）在D11染色体的24.2-24.8 Mb区域具有相同的QTL位点，此前报道的候选基因GhKRP6 （Ghir_D11G020340）位于该区间内。群体在D11染色体24.2-24.8 Mb内可分为3个单倍型，单倍型Hap1和Hap2的纤维长度大于Hap3，更多的纤维素和胼胝质的含量在Hap3中明显积累，与次生细胞壁纤维素合成相关的基因（CESA4、CESA7、CESA8）在Hap3中的平均表达水平明显高于Hap1和Hap2。 进一步对关键候选基因GhKRP6 （Ghir_D11G020340）进行遗传转化，验证了棉纤维发育过程中GhKRP6G通过对细胞壁多糖沉积的精确调控来控制棉花成熟纤维长度。将两个不同阶段纤维样本的代谢组数据集连接起来，对QTL q06:85-96.2 Mb热点和qFL9位点进行联合单倍型分析，最终提出了一个成熟纤维长度的遗传代谢调控模型。 该研究借助非靶向代谢物测定、细胞壁多糖测定，丰富了棉花mGWAS的相关研究，结合群体基因组信息和多年多点的群体成熟纤维表型，提出了成熟纤维长度的遗传调控模型，为通过遗传和精细地修改代谢物和细胞壁属性来改善成熟纤维长度提供了新思路。
[学术文献 ] MYB regulation of GST/GT mediates red petal spot development in cotton 进入全文
CROP JOURNAL
Red petal spots are beneficial for attracting cotton pollinators and producing hybrid seeds, and the anthocyanin pathway is generally regarded as a metabolic cause of petal coloration. The current study identified an MYB-encoding gene (Gar07G09390, GaMYB) as a candidate gene involved in cotton coloration by map-based cloning, and this MYB could positively regulate a candidate glutathione S transferase gene (Gar07G08900, GaGST). To unveil potentially involved genes within the GaMYB-regulating-GaGST route, color metabolites of both GaMYB- and GaGST-virus-induced gene silencing (VIGS) petals were investigated, revealing that they were largely glycosyl-decorated flavonoids. Accordingly, a transcriptomic survey of both VIGS petals identified a glycosyl-transferase gene (GaGT, Gar02G15390). Notably, this GaGT is adjacent to one of the genome-wide association study loci concerning petal spots in Gossypium arboreum, and it is also positively regulated by GaMYB. This new regulatory route including both GST and GT regulated by MYB is conserved among the three cotton species examined in this study (Gossypium arboreum, Gossypium hirsutum, and Gossypium barbadense). Accordingly, comprehensively evaluating the influence of these candidates and their homologs on cotton coloration may provide a more in-depth understanding of cotton coloration, ultimately facilitating the breeding of more colorful cotton.
[学术文献 ] Gossypium arboreum (L.): A review on its agronomic and industrial potential for sustainable cotton production 进入全文
PHYSIOLOGICAL AND MOLECULAR PLANT PATHOLOGY
Gossypium arboreum (L.), an ancient diploid cotton species native to the Indian subcontinent, holds substantial agronomic and industrial value due to its resilience to biotic and abiotic stresses and its potential for sustainable cotton production in the face of climate change. This review synthesizes current research on the agronomic, industrial, biochemical, and pharmacological attributes of G. arboreum, emphasizing its relevance as a resilient and multifunctional crop. Unlike the widely cultivated G. hirsutum, the species is naturally adapted to rainfed and low-input agricultural systems, displaying strong resistance to drought, pests, and major cotton diseases, making it suitable for organic and environmentally sustainable farming. Despite limitations in fiber length and fineness compared to tetraploid species like G. hirsutum, it has industrial applications in absorbent cotton, handlooms, and coarse yarn, and is now gaining recognition in niche markets for its naturally pigmented varieties. Recent breeding programs have aimed to improve its fiber quality while maintaining stress tolerance. G. arboreum also maintains fiber quality under water-deficit conditions, reinforcing its value in stress-prone regions. Unique biochemical features, particularly its GaCYP722C-mediated strigolactone biosynthesis, distinguish it from other Gossypium species, offering novel genetic insights for plant growth regulation and soil symbiosis. Phytochemically, it is rich in flavonoids, tannins, and terpenoids, which contribute to antidiabetic, antioxidant, and woundhealing properties. This pharmacological potential, along with its compatibility with sustainable textile applications, expands its industrial scope. By integrating genetic, agronomic, and phytochemical perspectives, this review identifies G. arboreum as a vital genetic resource for cotton improvement and climate-resilient agriculture.
[学术文献 ] Transcriptomic exploration yields novel perspectives on the regulatory network underlying trichome initiation in Gossypium arboreum hypocotyl 进入全文
FRONTIERS IN PLANT SCIENCE
Trichomes play a crucial role in plant stress tolerance and serve as an excellent model for studying epidermal cell differentiation. To elucidate the molecular mechanisms underlying trichome development in cotton stems, we investigated two Gossypium arboreum mutants that exhibit abnormal trichome patterns during hypocotyl growth. Based on morphological characteristics, we classified four developmental stages: preinitiation, initiation, elongation, and maturation. Comparative transcriptome profiling of epidermal cells across these stages identified differentially expressed genes (DEGs) through maSigPro analysis, which revealed that these DEGs were primarily associated with pathways involved in cell wall metabolism. Additionally, integrated weighted gene co-expression network analysis (WGCNA) and Cytoscape analyses identified 20 core regulatory genes from a total of 59 candidates linked to epidermal development. Utilizing three machine learning algorithms (SVM-RFE, Boruta, and LASSO), we consistently prioritized five key regulators: Ga02G1392 (TBR), Ga03G0474 (OMR1), Ga12G2860 (ACO1), Ga11G2117 (BBX19), and Ga12G2864 (CUE). RT-qPCR validation confirmed their stage-specific expression patterns, which were consistent with the RNA-Seq data. Our study establishes a comprehensive framework for research on cotton trichomes and identifies critical genetic components governing epidermal hair development, thereby providing new insights for the molecular breeding of stress-resistant cotton varieties.
[学术文献 ] Water stress reduces cellulose deposition in the cell wall and increases wax content, resulting in decreased fiber quality 进入全文
FRONTIERS IN PLANT SCIENCE
Introduction: Water deficiency reduces cotton fiber quality, but the underlying mechanisms behind this decline remain poorly understood. Although the cuticle is critical for plant water homeostasis under drought, few studies have addressed the relationship between water stress, fiber epidermal wax, and fiber quality. Thus, studying the interaction between fiber cuticular wax and quality is crucial for understanding plant drought tolerance and breeding superior drought-resistant cotton varieties. Methods: This experiment was designed as a randomized block design. Two cotton cultivars, Xincaimian7 (XC7, with high cuticular wax) and Shidamian217 (SD217, with low cuticular wax), were selected as materials. Two irrigation regimes were applied: well-watered (WW) and water-deficit (WD), each with three independent biological replicates. Results: Results showed WD irrigation significantly reduced the cotton fiber accumulation rate, particularly between 25-30 days post-anthesis (DPA). Compared with WW irrigation, the rate decreased by 23.62% and 30.82% respectively. WD treatment significantly inhibited the expression of the genes encoding sucrose synthase GhSusy and cellulose synthase GhCesA in cotton fibers. At 30 DPA, compared to the WW treatment, the sucrose contents in SD217 and XC7 fibers decreased by 18.66% and 12.85%, while cellulose contents dropped by 9.91% and 17.17%, respectively, resulting in a significant decrease in the thickness of the cell walls by 10.59% and 9.50% respectively. However, the WD treatment significantly induced the expression of wax synthesis-related genes in cotton fibers. Compared with the WW treatment, at 30 DPA, the epidermal wax contents of the fibers of SD217 and XC7 increased significantly by 81.87% and 97.34%, respectively. Correlation analysis reveals a significant positive relationship between fiber strength, length, and the contents of cellulose and sucrose (p<0.01). Conversely, a significant negative correlation exists between these fiber properties and wax content (p<0.01). Discussion: In summary, WD reduces the sucrose content in cotton fibers and induces wax accumulation. Thinner cell walls combined with a thicker wax layer altered the mechanical properties of the fibers, thus leading to a decrease fiber quality. Therefore, when breeding drought-tolerant varieties, breeders need to balance the drought resistance with the sucrose and wax characteristics of the fibers.
