优良抗病性是水稻绿色生产的重要需求,在当前水稻育种中有着举足轻重的地位.矮秆水稻具有耐倒伏、适合密植等优良特性,但其存在较高秆水稻生物产量低、密植易发生严重病害等问题,多年来困扰着水稻育种的研究,因此挖掘矮秆抗病资源成了...优良抗病性是水稻绿色生产的重要需求,在当前水稻育种中有着举足轻重的地位.矮秆水稻具有耐倒伏、适合密植等优良特性,但其存在较高秆水稻生物产量低、密植易发生严重病害等问题,多年来困扰着水稻育种的研究,因此挖掘矮秆抗病资源成了育种家们一直研究的热点.从EMS诱变处理的西农1B突变体库中鉴定到4个水稻矮化易感纹枯病突变体(Dwarf and susceptibility to sheath blight 1 mutants,dssb1s),遗传分析发现:这4个突变体均是在LOC_Os03g04680编码框中的不同位置发生突变,LOC_Os03g04680编码一个细胞色素酶OsCYP 96B4,接种水稻白叶枯病菌和纹枯病菌后发现这4个突变体均感病,qRT-PCR发现突变体中病程相关基因(NPR1,PR10,PR1a和WRKY45)表达量降低.组织切片和扫描电镜分析发现:突变体的叶片发育异常,叶表面硅化细胞的数量明显增多,分布密集、杂乱.对叶片和叶鞘的细胞壁成分测定发现:突变体中的木质素和纤维素质量分数均显著或极显著低于野生型.实验结果表明:OsCYP 96B4是通过调控植物的叶片等发育和细胞壁的组分,进而增强了对水稻病害的耐受性.展开更多
Epidermolysis bullosa simplex (EBS) is a mechano-bullous disorder characterized by intraepidermal blistering within the basal keratinocytes as a result of trauma to the skin. As part of the DNA diagnostics program, ou...Epidermolysis bullosa simplex (EBS) is a mechano-bullous disorder characterized by intraepidermal blistering within the basal keratinocytes as a result of trauma to the skin. As part of the DNA diagnostics program, our laboratory has analyzed a cohort of 57 patients with the initial referral diagnosis of EBS. Among these patients, 18 were found to harbor heterozygous mutations in the keratin 5 or keratin 14 genes, KRT5 and KRT14, respectively, whereas in 14 cases, the disease was associated with mutations in both alleles of the plectin gene. Among the keratin mutations, 12 were distinct and six were novel, and in most cases there was no family history of a blistering disease. Prenatal diagnosis of eight pregnancies with keratin gene mutations, at risk for EBS either because one of the parents was affected (three cases) or history of a previously affected child as a result of a de novo mutation (five cases), predicted two fetuses being affected and six being normal. No recurrence of the de novo mutations in these pregnancies was disclosed. Collectively, the data suggest that a significant number of cases diagnosed as EBS are due to plectin mutations, and many cases result from de novo mutations in KRT5 and KRT14 genes. These findings have implications for genetic counseling and prenatal diagnosis for EBS.展开更多
文摘优良抗病性是水稻绿色生产的重要需求,在当前水稻育种中有着举足轻重的地位.矮秆水稻具有耐倒伏、适合密植等优良特性,但其存在较高秆水稻生物产量低、密植易发生严重病害等问题,多年来困扰着水稻育种的研究,因此挖掘矮秆抗病资源成了育种家们一直研究的热点.从EMS诱变处理的西农1B突变体库中鉴定到4个水稻矮化易感纹枯病突变体(Dwarf and susceptibility to sheath blight 1 mutants,dssb1s),遗传分析发现:这4个突变体均是在LOC_Os03g04680编码框中的不同位置发生突变,LOC_Os03g04680编码一个细胞色素酶OsCYP 96B4,接种水稻白叶枯病菌和纹枯病菌后发现这4个突变体均感病,qRT-PCR发现突变体中病程相关基因(NPR1,PR10,PR1a和WRKY45)表达量降低.组织切片和扫描电镜分析发现:突变体的叶片发育异常,叶表面硅化细胞的数量明显增多,分布密集、杂乱.对叶片和叶鞘的细胞壁成分测定发现:突变体中的木质素和纤维素质量分数均显著或极显著低于野生型.实验结果表明:OsCYP 96B4是通过调控植物的叶片等发育和细胞壁的组分,进而增强了对水稻病害的耐受性.
文摘Epidermolysis bullosa simplex (EBS) is a mechano-bullous disorder characterized by intraepidermal blistering within the basal keratinocytes as a result of trauma to the skin. As part of the DNA diagnostics program, our laboratory has analyzed a cohort of 57 patients with the initial referral diagnosis of EBS. Among these patients, 18 were found to harbor heterozygous mutations in the keratin 5 or keratin 14 genes, KRT5 and KRT14, respectively, whereas in 14 cases, the disease was associated with mutations in both alleles of the plectin gene. Among the keratin mutations, 12 were distinct and six were novel, and in most cases there was no family history of a blistering disease. Prenatal diagnosis of eight pregnancies with keratin gene mutations, at risk for EBS either because one of the parents was affected (three cases) or history of a previously affected child as a result of a de novo mutation (five cases), predicted two fetuses being affected and six being normal. No recurrence of the de novo mutations in these pregnancies was disclosed. Collectively, the data suggest that a significant number of cases diagnosed as EBS are due to plectin mutations, and many cases result from de novo mutations in KRT5 and KRT14 genes. These findings have implications for genetic counseling and prenatal diagnosis for EBS.
