The reactive oxygen species network pathways: an essential prerequisite for perception of pathogen attack and the acquired disease resistance in plants

Availability of complete Arabidopsis(Arabidopsis thaliana) and rice(Oryza sativa) genome sequences, together with molecular recourses of functional genomics and proteomics have revolutionized our understanding of reactive oxygen species (ROS) signalling network mediating disease resistance in plants. So far, ROS have been associated with aging, cellular and molecular alteration in animal and plant cells. Recently, concluding evidences suggest that ROS network is essential to induce disease resistance and even to mediate resistance to multiple stresses in plants. ROS are obligatory by-products emerging as a result of normal metabolic reactions. They have the potential to be both beneficial and harmful to cellular metabolism. Their dual effects on metabolic reactions are dosage specific. In this review we focus our attention on cellular ROS level to trigger beneficial effects on plant cells responding to pathogen attack. By exploring the research related contributions coupled with data of targeted gene disruption, and RNA interference approaches, we show here that ROS are ubiquitous molecules of redox-pathways that play a crucial role in plant defence mechanism. The molecular prerequisites of ROS network to activate plant defence system in response to pathogen infections are here underlined. Bioinformatic tools are now available to scientists for high throughput analysis of cellular metabolisms. These tools are used to illustrate crucial ROS-related genes that are involved in the defence mechanism of plants. The review describes also the emerging findings of ROS network pathways to modulate multiple stress resistance in plants.     

转录组学平台技术及其在植物抗逆分子生物学中的应用

不利的环境条件是影响作物产量和生态环境的重要因素之一.植物抗逆分子生物学的研究是植物学领域的研究热点之一.转录组学与蛋白质组学技术是筛选抗逆基因以及揭示植物抗逆分子机制的主要技术.综述主要的转录组学平台技术的原理、特点及其在植物抗逆分子生物学中的应用.总结植物抗逆分子生物学研究面临的问题并对发展前景作出展望.     

Identification of two poorly prognosed ovarian carcinoma subtypes associated with CHEK2 germ-line mutation and non-CHEK2 somatic mutation gene signatures

High-grade serous ovarian cancer (HG-SOC), a major histologic type of epithelial ovarian cancer (EOC), is a poorly-characterized, heterogeneous and lethal disease where somatic mutations of TP53 are common and inherited loss-of-function mutations in BRCA1/2 predispose to cancer in 9.5–13% of EOC patients. However, the overall burden of disease due to either inherited or sporadic mutations is not known.

We performed bioinformatics analyses of mutational and clinical data of 334 HG-SOC tumor samples from The Cancer Genome Atlas to identify novel tumor-driving mutations, survival-significant patient subgroups and tumor subtypes potentially driven by either hereditary or sporadic factors.

We identified a sub-cluster of high-frequency mutations in 22 patients and 58 genes associated with DNA damage repair, apoptosis and cell cycle. Mutations of CHEK2, observed with the highest intensity, were associated with poor therapy response and overall survival (OS) of these patients (P = 8.00e-05), possibly due to detrimental effect of mutations at the nuclear localization signal. A 21-gene mutational prognostic signature significantly stratifies patients into relatively low or high-risk subgroups with 5-y OS of 37% or 6%, respectively (P = 7.31e-08). Further analysis of these genes and high-risk subgroup revealed 2 distinct classes of tumors characterized by either germline mutations of genes such as CHEK2, RPS6KA2 and MLL4, or somatic mutations of other genes in the signature.

Our results could provide improvement in prediction and clinical management of HG-SOC, facilitate our understanding of this complex disease, guide the design of targeted therapeutics and improve screening efforts to identify women at high-risk of hereditary ovarian cancers distinct from those associated with BRCA1/2 mutations.     

Identification of genes influencing formation of the Type III Brush Hair in Yangtze River Delta white goats by differential display of mRNA

Yangtze River Delta white goat is an exclusive indigenous Chinese goat breeds that can produce Brush Hair specialized in making valuable writing brush. The high-grade (Type III) Brush Hair is conical coarse hair but with a tip, which only grows in the cervical carina and back regions of Yangtze River Delta white goats. Screening of genes influencing the formation of Type III Brush Hair was conducted using differential display of mRNA technique in skin including the hair follicles of different goat groups and the differential bands were identified using reverse Northern dot blot, and the positive bands were subsequently cloned and sequenced. The results showed that 20 differentially displayed bands were obtained, seven of which were identified positive as expressed in skin. Three of these seven cDNAs were homologous to certain sequences from GenBank and the other four were respectively homologous to CKLF-like MARVEL transmembrane domain containing 3 (CMTM3), S100 calcium binding protein A4 (S100A4), protein kinase inhibitor gamma (PKIG) and fibulin 1-D. The study would provide a new view to elucidate their roles in hair growth and hair follicle cycle and increase our understanding of the formation of Type III Brush Hair.