Differentiation of Fungal Destructive Behaviour of Wood by the White-Rot Fungus Fomes fomentarius by MALDI-TOF Mass Spectrometry

There are many methods to identify and recognize the molecular and behavioural differences between organisms.One of the methods for the detection and identification of unknown organisms as well as intermolecular and intramolecular structural differences is MALDI-TOF mass spectrometry.Therefore,differentiation of Fomes fomentarius decay capabilities on the chemical properties of the wood cell wall of the tree species Quercus castaneifolia,Juglans regia,and Carpinus betulus were used to determine and characterize the destructive behaviour of F.fomentarius decay by MALDI-TOF mass spectrometry.The results showed that the fungus had more significant destructive behaviour on J.regia than the other species.For this evidence,completely removal of xylan hemicellulose fragment+Na+at peak 1227 Da and severe digestion of fragment of glucomannan hemicellulose at peak 1477–1480 Da that it seems that signs of soft-rot patterns were obtained from the decayed sample of J.regia,while these were incremental and unchanged for C.betulus and Q.castaneifolia,respectively.However,C.betulus had different peaks of atomic mass than J.regia and Q.castaneifolia wood,respectively.These results showed that this technique could be useful for separating and identifying unknown compounds of the wood cell wall attacked by fungi relying on their biological behaviour.

Effects of Exogenous Nitric Oxide and 24-Epibrassinolide on the Physiological Characteristics of Peanut Seedlings Under Cadmium Stress

Cadmium(Cd) is highly toxic to plants, animals, and humans. Limited information is available on the role of nitric oxide(NO)and/or 24-epibrassinolide(EBR) in response of plants to Cd stress. In this study, a hydroponic experiment was performed to investigate the effects of NO and/or EBR on peanut plants subjected to Cd stress(200 μmol L^(-1)) with sodium nitroprusside(SNP, an exogenous NO donor)(250 μmol L^(-1)) and/or EBR(0.1 μmol L^(-1)) addition. The results showed that Cd exposure inhibited plant growth, and this stress was alleviated by exogenous NO or EBR, and especially the combination of the two. Treatment with Cd inhibited the growth of peanut seedlings, decreased chlorophyll content, and significantly increased the Cd concentration in plants. Furthermore, the concentration of reactive oxygen species(ROS) markedly increased in peanut seedlings under Cd stress, resulting in the accumulation of malondialdehyde(MDA) and proline in leaves and roots. Under Cd stress, applications of SNP, EBR, and especially the two in combination significantly reduced the translocation of Cd from roots to leaves, increased the chlorophyll content, decreased the concentrations of ROS, MDA, and proline, and significantly enhanced the activities of superoxide dismutase(SOD), peroxidase(POD), and catalase(CAT) in peanut seedlings. Exogenous NO and/or EBR also stimulated the activities of nitrate reductase(NR)and nitric oxide synthase(NOS) and increased the contents of antioxidants, such as ascorbic acid(AsA) and reduced glutathione(GSH). Furthermore, exogenous NO and/or EBR enhanced Cd accumulation in the cell wall and thus decreased Cd distribution in the organelles in the roots. The concentrations of calcium(Ca), iron(Fe), magnesium(Mg), and zinc(Zn) were also regulated by exogenous NO or EBR, and especially by the two in combination. These results indicated that SNP and EBR, alone and particularly in combination, can mitigate the negative effects of Cd stress in peanut plants.

Characterization of maize leaf pyruvate orthophosphate dikinase using high throughput sequencing

In C4 photosynthesis, pyruvate orthophosphate dikinase （PPDK） catalyzes the regeneration of phospho- enolpyruvate in the carbon shuttle pathway. Although the biochemical function of PPDK in maize is well characterized, a genetic analysis of PPDK has not been reported. In this study, we use the maize transposable elements Nlutator and Ds to generate multiple mutant alleles of PPDK. Loss-of- function mutants are seedling lethal, even when plants were grown under 2% CO2, and they show very low capacity for CO2 assimilation, indicating C4 photosynthesis is essential in maize. Using RNA-seq and GC-MS technologies, we exam- ined the transcriptional and metabolic responses to a deficiency in PPDK activity. These results indicate loss of PPDK results in downregulation of gene expression ofenzymes of the C4 cycle, the Calvin cycle, and components of photochemistry. Furthermore, the loss of PPDK did not change Kranz anatomy, indicating that this metabolic defect in the C4 cycle did not impinge on the morphological differentiation of C4 characters. However, sugar metabolism and nitrogen utilization were altered in the mutants. An interaction between light intensity and genotype was also detected from transcriptome profiling, suggesting altered transcriptional and metabolic responses to environmental and endogenous signals in the PPDK mutants.