The Hebrew University of Jerusalem reported that a team of Israeli scientists has developed Xanthoma, a new tomato variety that can help fight degenerative eye diseases. This new tomato is rich in zeaxanthin, a fat-soluble pigment whose function is to protect the plant against solar radiation, which could inhibit degenerative diseases by protecting the retina's light receptors from damage caused by ultraviolet radiation. This natural yellow pigment can be found mainly in corn, orange peppers, squash, and citrus, and in very low concentrations in melons, mangoes, apricots, and peaches. The researchers, led by Professor Joseph Hirschberg, who specializes in plant genetics, molecular biology, and genetic engineering, said that adding zeaxanthin to a daily diet helps reduce the development of degenerative diseases, especially macular degeneration, which causes blindness in adults. Hirschberg noted that Xanthomate - named for xanthophyll, the group of substances to which zeaxanthin belongs - was developed using classical genetic cultivation and hybridizations of different strains. Zeaxanthin makes up more than half of the new tomato's pigments, which also has the vitamins and other essential nutrients found in common tomatoes, he noted. In fact, the new tomato strain has seven times more zeaxanthin than corn, which is the main source of this substance in today's diet. "As far as we know, this is the highest level of zeaxanthin achieved in any major agricultural crop in the world," the researchers noted.
杂种优势利用是提高作物产量的有效途径。杂交种往往比双亲具有更高的产量和更好的抗性。作物杂交种培育依赖于雄性不育系与父本的杂交来生产子代杂交种。因此，作物雄性不育系的培育和维持是杂种优势利用的重要前提。目前生产上使用的作物雄性不育系主要分为稳定的细胞质不育系和不稳定的细胞核不育系两类，不仅其创制过程极为复杂，在生产上也存在很多限制。 2020年7月8日，Molecular Plant 在线发表了中国农业科学院谢传晓和李新海研究员领导的研究团队题为“Genome Editing Enables Next-Generation Hybrid Seed Production Technology“的研究论文，报道了基于基因编辑技术发展了新一代作物不育系和杂交种培育的简易方法。鉴于该研究具有重要的生产应用价值，我们有幸邀请到中科院遗传所高彩霞研究员与华南农业大学王海洋教授对该论文研究工作分别做了点评与详细解读。
近期，《Plant Biotechnology Journal》在线发表了扬州大学园艺与植物保护学院欧阳寿强教授团队的题为 “SlymiR482e-3p mediates tomato wilt disease by modulating ethylene response pathway” 研究论文。该研究报道了番茄內源SlymiR482e-3p在番茄抗枯萎病过程中的功能，揭示了其通过调控靶基因SlSGT1的表达介导乙烯信号传递通路以应答病原菌入侵的分子机制。 番茄果实营养丰富，具特殊风味，是全世界重要的蔬菜作物之一，同时番茄还是研究植物生物学的一个重要模式生物。尖孢镰刀菌是重要的土传病害，引起作物枯萎病，被公认为世界上三大土传病原真菌之一。欧阳寿强教授团队长期关注的番茄枯萎病是由镰刀菌属真菌番茄尖孢镰刀菌（Fusarium oxysporum f. sp. Lycopersici）引起的一种番茄病害，给番茄农业生产造成巨大的经济损失。目前，以果蔬枯萎病病原菌的防治为中心开展的尖孢镰刀菌致病机理以及寄主抗病防御的研究越来越被关注，但围绕番茄抗枯萎病，尤其是从整体上对番茄与尖孢镰刀菌两者之间互作机制的研究有待进一步深入探索。欧阳寿强教授团队前期研究报道了番茄内源miRNA，SlymiR482e-3p，在尖孢镰刀菌入侵番茄根系时表达下调，并调控其抗病相关基因的表达参与番茄抗枯萎病的过程。本研究报道了SlymiR482e-3p一个新的靶基因SlSGT1，结合SlymiR482e-3p敲除突变体材料在病原菌侵入条件下转录组分析结果，揭示了SlymiR482e-3p通过调控SlSGT1的表达，并以某种未知的方式介导乙烯信号通路以应答病原菌入侵的分子机制。该研究拓展了番茄抗枯萎病的机理研究，同时也为进一步深入探讨其精准的调控方式提出了新的研究方向。 硕士研究生高颖和李思健为该论文的共同第一作者，欧阳寿强教授为通讯作者。该研究得到国家自然科学基金、江苏省自然科学基金、扬州大学高层次人才基金共同资助。
以早抽薹 ‘S-1’ 与晚抽薹 ‘G-1’ 为亲本，构建F1、BC1、BC2和F2群体，采用植物数量性状主基因+多基因混合遗传模型分析法对结球甘蓝抽薹性状进行遗传分析，并采用SLAF-BSA方法对抽薹时间进行QTL定位分析。结果显示，结球甘蓝抽薹性状是由2对加性-显性-上位性主基因+加性-显性多基因遗传控制；主基因 + 多基因平均遗传率是93.41%。共检测到2个QTLs，分别为C02染色体上的2.31 ～ 3.09 Mb和33.57 ～ 34.40 Mb，总长度为1.61 Mb。
[学术文献] Rapid identification of yellow-flowered gene Bofc in cauliflower (Brassica oleracea var. botrytis) by bulked segregant analysis and whole-genome resequencing 进入全文
The accumulation of carotenoids is related to pigment formation in flowers and other organs. In order to elucidate the genetic variation of flower color in cauliflower, a F2 segregating population was obtained from yellow-flowered cauliflower‘QGS’ and white-flowered Chinese kale ‘JYJ’. Bulked segregant analysis combined with the whole-genome resequencing was employed to locate the target region for Flower Color. In this study, Bofc was anchored on chromosome C03 with a single peak, and further mapped to 164 kb interval with 0.28 cM genetic distance. BoCCD4, encoding carotenoid cleavage dioxygenase 4 in the carotenoid metabolic pathway, was selected as the most likely candidate gene. Sequence analysis revealed that an insertion of a 10,608 bp CACTA-like transposon in the coding region led to the loss-of-function of the BoCCD4 gene in cauliflower. These results will provide further understanding of the genetic mechanism controlling flower color in Brassica oleracea species.
[学术文献] Phylogenetic relationships and genetic structure of populations of turnip mosaic virus in Turkey 进入全文
European Journal of Plant Pathology
Surveys were carried out throughout Turkey and a total of 437 symptomatic samples were collected from winter vegetables and weeds, most of which belong to the Brassicaceae family. Testing the collected samples for the presence of turnip mosaic virus (TuMV) by double antibody sandwich-enzyme linked immunosorbent assay (DAS-ELISA) and reverse transcription-polymerase chain reaction (RT-PCR) confirmed that 117 samples were infected with TuMV. In total, 20 out of 117 TuMV-infected samples representing different regions and host plants were then selected and further analyzed for biological and molecular characteristics. As a result of biological indexing studies, two host infecting types of TuMV, i.e., B and BR were identified in Turkish TuMV isolates. The partial genomic sequences of the nuclear inclusion b protein and coat protein genes (NIb+CP region) of these isolates were determined. The corresponding sequence of the remaining 61 Turkish TuMV isolates were retrieved from GenBank for further analysis. The phylogenetic analysis showed that Turkish isolates fell into the basal-B, Asian-BR, and world-B phylogenetic groups. The evolutionary divergence value of Turkish isolates in the basal-B, Asian-BR, and world-B phylogroups were determined as 0.0026, 0.0134, and 0.0065 at nucleotide level; 0.0243, 0.0102, and 0.0129 at the amino acid level, respectively. Genetic structure analysis of Turkish TuMV isolates revealed that some isolates were admixed or had migrated among different subgroups. Our analysis provides the first depth study for the biological characteristics and genetic structures of Turkish TuMV populations.