希金斯刺盘孢全基因组候选效应分子的预测

希金斯刺盘孢（Colletotrichum higginsianum Sacc.）是一种世界性分布的重要植物病原真菌，可引起严重的十字花科植物炭疽病，影响作物品质并造成严重的经济损失。效应分子在植物病原真菌侵染寄主植物过程中发挥着重要的作用。根据已公布的希金斯刺盘孢的全基因组信息，以其全基因组蛋白序列为材料，通过生物信息学方法，对其候选效应分子及其功能进行了预测和分析。首先利用SignalP、TMHMM、Protcomp、big-PI Predictor 和TargetP程序依次预测出其分泌类型的蛋白，再通过其序列大小和半胱氨酸含量作进一步筛选，最后利用blastp工具与非冗余蛋白质数据库进行比对，找出数据库中没有蛋白同源性的序列，从而获得候选效应分子；同时对希金斯刺盘孢全基因组的16 150个蛋白序列进行分析，最终预测到135个符合条件的候选效应分子，而大多数都是功能未知的假定蛋白。本研究采用生物信息学分析方法预测出了希金斯刺盘孢的候选效应分子，为进一步研究这些效应分子的功能奠定了基础，其研究技术和手段也为其它真菌效应分子的预测提供了重要的参考资料。     

XopN-T3SS effector modulates in planta growth of Xanthomonas axonopodis pv. punicae and cell-wall-associated immune response to induce bacterial blight in pomegranate

Bacterial blight caused by Xanthomonas axonopodis pv. punicae (Xap) is an important disease of pomegranate. Most phytopathogenic strains in the Genera Xanthomonas secrete effector proteins by the type III secretion system (T3SS) to suppress pathogen-associated molecular pattern (PAMP)-triggered plant immunity (PTI). The T3SS effectors, referred to as Xanthomonas outer proteins (Xops), are known to be key factors required for bacterial growth and colonization in distinct eukaryotic hosts. Xap contains six Xop-effectors, namely XopC2, XopE1, XopL, XopN, XopQ and XopZ. In this study we analyzed xopN, a conserved effector in Xanthomonas, with reference to sequence identity and its role in governing bacterial growth, and virulence. The xopN of Xap shared maximum sequence identity (98.6%) with pathovar citri. Overlapping extension PCR and double crossing over based homologous recombination strategy was employed to generate a xopN null mutant (Xap ΔxopN) of Xap. A kanamycin gene was used to replace the xopN gene. XopN was required for maximal Xap pathogenicity in its natural host pomegranate. The detailed image analysis on blight lesions revealed 3 fold reduction in watersoaked areas on leaves infiltrated with mutant Xap ΔxopN compared to that of with wild Xap. The in planta population count of Xap ΔxopN was reduced approximately 32-fold relative to the wild strain indicating that xopN is required for maximal growth of Xap in pomegranate. In addition, the Xap ΔxopN mutant induced more callose deposition in infected pomegranate leaves. Taken together, the present study shows that XopN governs Xap growth and modulates cell-wall associated immune response in pomegranate.     

玫烟色棒束孢基因组候选效应因子的预测分析

在玫烟色棒束孢（Isaria fumosorosea）全基因组10 061个蛋白质序列的基础上,经过SignalP v4.1分析得到1 112个具有信号肽的蛋白序列;以此为基础用TMHMM v2.0分析得到1 030个跨膜数小于2的蛋白序列;1 030个具有信号肽的蛋白经过TargetP v 1.1分析得到1 001个定位为S的蛋白序列;最后经过ProtComp v 9.0分析,得到929个蛋白质定位于细胞质中的分泌蛋白序列。929个蛋白中包含半胱氨酸含量大于等于6的蛋白序列共495个,其中146个蛋白序列的串联重复序列大于或等于9。共137个蛋白在病原物-寄主互作数据库（Pathogen-host interaction database,PHI）中获得注释,其中91个蛋白为候选效应蛋白。挑取小于300个氨基酸的蛋白序列,共筛选到19个候选效应因子。最终从10 061个蛋白序列中筛选得到19个候选致病效应因子。     

Applied Biotechnology to Combat Late Blight in Potato Caused by <Emphasis Type="Italic">Phytophthora Infestans</Emphasis>

Potato is an important crop, grown worldwide. It suffers from many pests and diseases among which late blight, caused by the oomycete Phytophthora infestans, is the worst. The disease is still causing major damage in many potato production areas and control is only possible by applying fungicides frequently. The knowledge on the molecular biology and genetics of the interaction between the plant and the oomycete is developing rapidly. These are relevant fields of study, currently dominated by the discovery of many resistance genes and numerous effector proteins and the analysis of their specific mode of action. These studies may yield essential information needed for the development of durable resistance. The long-term and worldwide effort to breed for resistance so far has had little effect. A novel breeding approach may change this. It is based on cisgenic modification (CM) consisting of marker-free pyramiding of several resistance genes and their spatial and temporal deployment yielding dynamic varieties that contain potato genes only. It is envisioned that this CM approach with potato’s own genes will not only prove societally acceptable but may also result in simplifications in the legislation on use of the CM approach. Various parties in the potato research arena intend to cooperate in this novel approach in a number of developing countries where potato substantially contributes to food security. The use of resources such as land, water and energy improves when the effect of late blight is markedly reduced.     

新疆南部地区长绒棉生长可视化研究

在综合国内外相关研究成果的基础上,运用系统分析原理和数学建模技术,构建符合长绒棉生长的器官集合属性分析模型、根结构模型、器官空间形态机理模型和植株拓扑结构动态模型,并最终实现南疆长绒棉动态三维图形模拟。该系统可促进人们对南疆长绒棉生长过程的理解和感知,为分析长绒棉结构功能关系、设计理想株型和调控生长模式等提供支持。