蔬菜育种专题

2017年第43期总105期

蔬菜育种专题

本期导读

前沿资讯

1．应用CRISPR基因编辑技术打破作物产量障碍

学术文献

1．印度甘蓝品种子叶和下胚轴再生植株的高频培养

2．芥菜型油菜在短期盐胁迫条件下的生理、生化过程和基因表达的变化

3．控制条件下春甘蓝型油菜耐热性遗传特性的全基因组关联研究

4．CRISPR/Cas9介导的基因编译技术在甘蓝型油菜中利用一条sgRNA产生多个位点特异性突变

中国农业科学院农业信息研究所

联系人：王爱玲

邮箱：agri@

2017年10月23日

前沿资讯

1．Plant geneticists develop a new application of CRISPR to break yield barriers in crops(应用CRISPR基因编辑技术打破作物产量障碍)简介：冷泉港实验室（CSHL）的科学家正在研究开发基因编辑技术提高农作物产量的潜能。以番茄为例，他们利用CRISPR/Cas9技术快速生成变异植株，表现为三个重要的农业性状：果实大小、分支结构和植物的整体形状，这些都是决定植株产量的主要因子。这种方法适用于所有食物、饲料和燃料作物，包括主食大米、玉米、高粱和小麦。

主持项目研究的冷泉港实验室Zachary Lippman教授认为，目前的作物产量不能满足全球未来人口增长的需求，其中一个最大的限制是自然界没有提供足够的遗传变异供育种工作者使用，特别是对于可能涉及几十个基因的主要产量性状。冷泉港实验室已经利用CRISPR技术产生新的遗传变异，可以促进作物改良并使其结果更可预测。

研究小组的实验结果发表在2017年9月14日在线出版的《细胞》杂志上，包括使用CRISPR“剪刀”在三个被称为“启动子”的番茄基因组序列进行多次剪切，这个DNA区域附近的相关基因能够帮助调节产量基因何时何地以及在什么水平上是活跃的。这样，在每个调控区域内产生了一组突变，研究人员就能够在三个目标性状上获得广泛变异。

利用CRISPR技术产生新的遗传性状变异的能力，植物的每个特性可以通过一个控制灯泡的调光开关方式来控制，育种者就可以人为地调整植物以适应环境。

利用CRISPR变异调控与“产量”相关的基因，可以实现对数量性状的一个更微妙的影响。微调基因表达，比删除或失活其编码蛋白质，更有可能有利于商业化的农业生产，因为这种遗传变异提供了改善产量性状的灵活性。

传统育种需要耗费很多的时间和精力，将那些相关基因的有益变异集合在一起，从而培育出最佳的品种，这一品种还需要持续不断地改进。而基因编辑技术则可以通过直接生成和选择最有希望的变异基因来避开这种限制，这有助于打破产量壁垒。

每一个突变的区域被称为数量性状位点（QTL）。在任何给定的植物中，QTL的自然产生历时数千年，是自然突变导致产量性状微妙变化的结果。从自然界中寻找和利用QTL 一直是植物育种工作者的目标，但最有价值的QTL导致性状的细微变化是罕见的。Lippman和他的团队已经表明CRISPR生成的QTL可以结合现有的QTL创造遗传变异的“工具箱”，远超于在自然界中发现的遗传变异数量。

这项研究由皮尤拉美奖学金、美国国家自然科学基金博士后研究奖学金、国家自然科学基金植物基因组研究计划资助。

来源：Cold Spring Harbor Laboratory

发布日期：2017-09-17

全文链接：

/news-and-features/plant-geneticists-develop-a-new-appli cation-of-crispr-to-break-yield-barriers-in-crops.html

学术文献

1．High frequency regeneration of plants from cotyledon and hypocotyl cultures in Brassica oleracea cv. Pride of India(印度甘蓝

品种子叶和下胚轴再生植株的高频培养)

简介：Morphogenic potential of cabbage cv. Pride of India, for multiple shoot induction was tested under in vitro conditions using cotyledon and hypocotyl explants. Aseptically grown seven to nine days old seedlings of cabbage were used as source of explants for reproducible plant regeneration studies. Forty different concentrations and combinations of TDZ (alone), TDZ with adenine, TDZ with NAA and TDZ with IAA were tried. Maximum shoot regeneration response from cotyledon explants (91.11%) and hypocotyl (94.40%) was obtained on MS medium containing 0.330mg/l TDZ+79.70mg/l Adenine and 0.220mg/l TDZ+0.088mg/l IAA, respectively. Rooting was achieved within two to three weeks on all the rooting media, but MS medium containing 0.10mg/l NAA produced the maximum number of strong and healthy roots (100%). The regenerated complete plantlets with healthy roots and shoot system were transferred to pots containing sterilized cocopeat and successfully acclimatized and no phenotypic variations were observed among regenerated plants. Highly efficient, reproducible plant regeneration protocol has been standardized in cabbage cv. Pride of India, which would be valuable for Agrobacterium-mediated gene transfer studies in cabbage.

来源：Biotechnology Reports

发布日期：2017-02-28

全文链接：

/ass/c9fbaaa9-8999-43ec-98ce-fbc235a93235.pdf 2．Time course of physiological, biochemical, and gene expression changes under short-term salt stress in Brassica juncea L.(芥菜型油

菜在短期盐胁迫条件下的生理、生化过程和基因表达的变化)

简介：Salinity-imposed limitations on plant growth are manifested through osmotic and ionic imbalances. However, because salinity-induced responses vary considerably among crop plants, monitoring of such responses at an early stage has relevance. In this study, physiological (seed germination, seed vigor index, root length, shoot length, fresh weight, dry weight) and biochemical attributes (osmoprotectants, K+/Na+ ratio) were analyzed for a time-course assessment of salt responses in Indian mustard (Brassica juncea L.) with an emphasis on early monitoring. The results showed strong correlations for total soluble sugars at germination phase (24 h), proline content in the seedling establishment phase (48 h) and various physiological parameters including seed vigor index (R2=0.901), shoot length (R2=0.982), and fresh weight (R2=0.980) at 72 h (adaptation under stress). In addition, transcriptional changes were observed under NaCl treatment for key genes belonging to the family of selective ion transporters (NHX, HKT) and abscisic acid synthesis (AAO-3). The status of mitochondrial respiration was also examined as a probe for salinity tolerance at an early stage. The results suggested that although all the analyzed parameters showed correlations (negative or positive) with salt stress magnitude, their critical response times differed, with most of the studied biochemical, physiological, or molecular markers providing valuable information only after radicle emergence, whereas mitochondrial respiration via alternative oxidase was useful for the early detection of salt responses.