A functional cutin matrix is required for plant protection against water loss

The plant cuticle, a cutin matrix embedded with and covered by wax, seals the aerial organ''s surface to protect the plant against uncontrolled water loss. The cutin matrix is essential for the cuticle to function as a barrier to water loss. Recently, we identified from wild barley a drought supersensitive mutant, eibi1, which is caused by a defective cutin matrix as the result of the loss of function of HvABCG31, an ABCG full transporter. Here, we report that eibi1 epidermal cells contain lipid-like droplets, which are supposed to consist of cutin monomers that have not been transported out of the cells. The eibi1 cuticle is fragile due to a defective cutin matrix. The rice ortholog of the EIBI1 gene has a similar pattern of expression, young shoot but not flag leaf blade, as the barley gene. The model of the function of Eibi1 is discussed. The HvABCG31 full transporter functions in the export of cutin components and contributed to land plant colonization, hence also to terrestrial life evolution.Key words: ABC transporter, cuticle, cuticular wax, drought resistance, inclusion     

Orchestrating a biomarker panel with lncRNAs and mRNAs for predicting survival in pancreatic ductal adenocarcinoma

The low survival of patients with pancreatic ductal adenocarcinoma (PDAC) makes the treatment of this disease one of the most challenging task in modern medicine. Here, by mining a large‐scale cancer genome atlas data set of pancreatic cancer tissues, we identified 21 long noncoding RNAs (lncRNAs) that significantly associated with overall survival in patients with PDAC (P < .01). Further analysis revealed that 8 lncRNAs turned out to be independently correlated with patients’ overall survival, and the risk score could be calculated based on their expression. To obtain a better predicting power, we integrated lncRNA data with a total of 410 differently expressed messenger RNAs (mRNAs) screened from PDAC and normal tissues in gene expression omnibus (GEO) database. The integration resulted in a much better panel including 8 lncRNAs (RP3.470B24.5, CTA.941F9.9, RP11.557H15.3, LINC00960, AP000479.1, LINC00635, LINC00636, and AC073133.1) and 8 mRNAs (DHRS9, ONECUT1, OR8D4, MT1M, TCN1, MMP9, DPYSL3, and TTN) to predict prognosis. A functional evaluation showed that these lncRNAs might play roles in pancreatic secretion, cell adhesion, and proteolysis. Using normal and pancreatic cancer cell lines, we confirmed that a majority of identified lncRNAs and mRNAs showed altered expressions in pancreatic cancer cells. Especially, LINC01589, LINC00960, TCN1, and MT1M showed a profoundly increased expression in pancreatic cancer cells, which suggests their potentially important role in pancreatic cancer. The results of our work indicate that lncRNAs have vital roles in PADC and provide new insights to integrate multiple kinds of markers in clinical practices.     

Regulation of extracellular acid phosphatase biosynthesis by culture conditions in entomopathogenic fungusMetarhizium anisopliae strain CQMa102

Metarhizium anisopliae is an imperfect entomopathogenic fungus. Once invading into its host,M. anisopliae needs to absorb basic nutrients such as phosphorus from the host haemolymph. A large number of phosphorylated compounds in haemolymph cannot be directly utilised by the fungal cell and must be hydrolysed into available form by phosphatase before ingested. Aims of this paper were to investigate optimum fermentation conditions for production of acid phosphatase and phosphatase isoenzymes byMetarhizium anisopliae. The optimum fermentation conditions were: glucose, 20 g/l; (NH₄)₂SO₄, 2 g/l; casein, 4 g/l; MgSO₄, 0.5 g; KCl, 0.5 g; microelement salt solution, 10 ml; inoculum size, 1×10⁷ spores per 100 ml medium; initial medium pH, 6.0. Under these conditions, the highest total acid phosphatase activity was 3.05 U/ml in 4 days at 27 °C and 160 rpm. Synthesis of the acid phosphatase was repressed by 0.01% inorganic phosphate in culture medium. The spectrum of isoenzymes produced byM. anisopliae varied depending on the phosphorus source employed in the culture. A specific isoform with pI 9.45 was induced by casein, and another isoform of pI 8.21 was induced by phytic acid and disodium phenyl phosphate.     

Enhanced Intracellular Reactive Oxygen Species by Photodynamic Therapy Effectively Promotes Chemoresistant Cell Death

Anti-cancer chemo-drugs can cause a rapid elevation of intracellular reactive oxygen species (ROS) levels. An imbalance in ROS production and elimination systems leads to cancer cell resistance to chemotherapy. This study aimed to evaluate the mechanism and effect of ROS on multidrug resistance in various human chemoresistant cancer cells by detecting the changes in the amount of ROS, the expression of ROS-related and glycolysis-related genes, and cell death. We found that ROS was decreased while oxidative phosphorylation was increased in chemoresistant cells. We verified that the chemoresistance of cancer cells was achieved in two ways. First, chemoresistant cells preferred oxidative phosphorylation instead of anaerobic glycolysis for energy generation, which increased ATPase activity and produced much more ATP to provide energy. Second, ROS-scavenging systems were enhanced in chemoresistant cancer cells, which in turn decreased ROS amount and thus inhibited chemo-induced cell death. Our in vitro and in vivo photodynamic therapy further demonstrated that elevated ROS production efficiently inhibited chemo-drug resistance and promoted chemoresistant cell death. Taken together, targeting ROS systems has a great potential to treat cancer patients with chemoresistance.     

贵州茶区茶树生态因子评述

贵州是茶树原产地之一,省内平均海拔在1000m以上的地区,占总面积的56.1%,由于山高多雾,茶叶自然品质较好,鲜叶主要化学成分含量丰富,且成分比率协调,所产中小叶种红碎茶及珍品名茶都匀毛尖、羊艾毛峰、遵义毛峰、湄江茶等,在国内外享有盛名,是我国南方得天独厚的茶区。本文拟从该区自然条件出发,着重阐述区内气候、土壤、海拔等生态因子对茶树生长及茶叶品质的影响,在此基础上,提出改善茶园生态条件的主要治理措施,以提供生产上参考。     

中国唇形科植物的一些新组合和新异名

正唇形科是有花植物的第6大科,具有重要的经济价值(DrewSytsma,2012)。该科植物全球广泛分布,共236属7,200余种(Harley et al,2004),我国有该科植物96属970余种(LiHedge,1994),为唇形科的6个多样性中心之一(Harley et al,2004)。近年来,我们对国内唇形科和一些重要类群进行了分类修订及系统学研究,并随之作了相应的命名处理     

Characterization and genetic mapping of the β-diketone deficient <Emphasis Type="Italic">eceriferum-b barley</Emphasis> mutant

Key message

The barley eceriferum-b.2 (cer-b.2) mutant produces glossy leaf sheaths and is deficient in the cuticular wax component 14,16-hentriacontanedione. The mutated gene maps to a 1.3-cM interval on chromosome 3HL flanked by the genes MLOC_10972 and MLOC_69561.

Abstract

The cuticular wax coating of leaves and stems in many grass species is responsible for the plants’ glaucous appearance. A major component of the wax is a group of β-diketone compounds. The barley eceriferum-b.2 (cer-b.2) mutant produces glossy leaf sheaths and is deficient for the compound 14,16-hentriacontanedione. A linkage analysis based on 708 gametes allowed the gene responsible for the mutant phenotype to be mapped to a 1.3-cM interval on chromosome 3HL flanked by the two genes MLOC_10972 and _69561. The product of the wild type allele may represent a step in the β-diketone synthesis pathway.

     

The abundance of certain metabolites responds to drought stress in the highly drought tolerant plant <Emphasis Type="Italic">Caragana korshinskii</Emphasis>

Metabolomics offers opportunities for studying the systematic response of an organism to a genetic and/or an environmental change. Here, the metabolic consequences of drought stress were characterized in the highly drought tolerant plant Caragana korshinskii. The time-of-flight mass spectrometry platform employed identified several hundred metabolites in extracts of the leaf, stem, root collar, and root of plants which had been either subjected to drought stress or were well-watered. Each of the four organs harbored a number of potential metabolite markers for the drought response. An increased abundance of various small carbohydrates and soluble amino acids in each of the four organs was induced by the stress; these compounds may act as compatible solutes or antioxidants. Across the whole plant, there was a fall in the content of several Krebs cycle and glycolysis intermediates, as well as in that of the amino acids glutamic acid and aspartic acid. Pathway analysis suggested that most of the potential metabolite markers were involved in energy metabolism and amino-acid metabolism. The implication was that energy metabolism and photosynthesis are compromised during the adaptation of C. korshinskii to drought stress. Given the different spectrum of metabolites associated with the drought response in the four organs, it was concluded that each organ employs a distinct strategy to cope with drought stress.