The enzymic conversion of hydroxycinnamic acids to p-coumarylquinic and chlorogenic acids in tomato fruits

Two enzymes thought to be involved in the biosynthesis of chlorogenic acid have been separated and purified by ion exchange chromatography and their properties studied. These two enzymes, p-coumarate CoA ligase and hydroxycinnamyl CoA: quinate hydroxycinnamyl transferase, acting together catalyse the conversion of p-coumaric acid to 5′-p-coumarylquinic acid and of caffeic acid to chlorogenic acid. The ligase has a higher affinity for p-coumaric than for caffeic acid and will in addition activate a number of other cinnamic acids such as ferulic, isoferulic and m-coumaric acids but not cinnamic acid. The transferase shows higher activity and affinity with p-coumaryl CoA than caffeyl CoA. It also acts with ferulyl CoA but only very slowly. The enzyme shows high specificity for quinic acid; shikimic acid is esterified at only 2% of the rate with quinic acid and glucose is not a substrate. The transferase activity is reversible and both chlorogenic acid and 5′-p-coumarylquinic acids are cleaved in the presence of CoA to form quinic acid and the corresponding hydroxycinnamyl CoA thioester.     

Selective degradation of altered tomato β-fructofuranosidase molecules by neutral protease

Evidence is presented for the selective breakdown of altered tomato β-fructofuranosidase molecules by a neutral protease from Bacillus subtilis.     

Age as a factor in induction of systemic acquired resistance in tomato against bacterial speck by aqueous fruit extracts of Azadirachta indica

In the present study, the effect of aqueous fruit extracts of Azadirachta indica on activity of Peroxidase (POX) at different ages of Tomato (Lycopersicon esculentum) leading to induction of systemic resistance against Pseudomonas syringae pv. tomato was evaluated. For this evaluation, four ages, that is, 6, 8, 10 and 12?weeks of plants were selected. A single leaf at the third node from base of each plant was treated either singly or with different combinations of Neem extract and pathogen. Samples were collected at an interval of 24?h for up to five days and after two weeks of the treatment from both treated and untreated nodes. The change in the activity of defence enzyme POX and expression of its isoforms was studied. The results demonstrate that systemic acquired resistance induced by the Neem fruit extract increases as the plant matures but it is not only the limiting factor.     

Foraging strategies of the acellular slime moulds Didymium iridis and Didymium bahiense

Organisms can increase their foraging efficiency by modifying their behaviour according to information about the quality of currently exploited resource patches. Here we examine the effect of food concentration on the foraging strategies of two previously unstudied species of slime mould: Didymium iridis and Didymium bahiense. We studied two main foraging decisions: how long to wait before commencing exploration of the surrounding environment (exploitation strategy) and how intensely to search the environment for new opportunities (exploration strategy). Food concentration did not affect exploitation behaviour in either D. iridis or D. bahiense. Food concentration did affect exploration behaviour in D. iridis, but not in D. bahiense. Encounters with food resources, irrespective of concentration, resulted in increased exploitation and decreased exploration in D. iridis but did not influence foraging behaviour in D. bahiense. We suggest that the varying foraging strategies of slime moulds may have evolved to exploit different resource distributions in their natural environments. We also discuss the potential impact of microbial contamination and differences in handling regimes.     

Bio-control activity of Purpureocillium lilacinum strains in managing root-knot disease of tomato caused by Meloidogyne incognita

The potential of 24 indigenous isolates of Purpureocillium lilacinum (Paecilomyces lilacinus) (Thom) Samson collected from different agro-climatic zones of India was investigated against the root-knot nematode, Meloidogyne incognita. The studies were conducted in vitro (larvicidal, ovicidal and egg-parasitising capacity) and under naturally infested field conditions with selected strains. Repeated field trials were conducted with talc-based preparations of fungal strains at 10 kg ha^?1, which were applied mixed in farm yard manure (FYM) at 1.5 t ha^?1. Results (in vitro) showed that all tested isolates were capable to parasitise eggs, inhibit egg hatching and cause juvenile mortality of M. incognita at various levels. Based on the performance under in vitro studies, eight isolates (NDPL-01, ANDPL-02, SHGPL-03, HYBPL-04, AHDPL-05, PTNPL-06, SNGPL-07 and VNSPL-08) were re-tested to confirm the results. HYBDPL-04 was found causing highest mortality (80%), inhibition of egg hatching (90%) as well as parasitisation of M. incognita eggs (75%). Under field trials also, the best protection of root-knot disease of tomato (Lycopersicon esculentum L.), in terms of reduction of galls (61%) and reproductive factor (P_f/P_i (RF) = 0.2) was achieved through application of HYBDPL-04 + FYM compared to control and other tested isolates. It also enhanced marketable yield of tomato up to 43%. It is concluded that the HYBDPL-04 strain of P. lilacinum is highly effective for management of root-knot disease of tomato under naturally infested field conditions. It is the isolate which produced the maximum number of metabolites which were extracted through high pressure liquid chromatography.     

iTRAQ‐Based Proteomics Reveals that the Tomato ms1035 Gene Causes Male Sterility through Compromising Fat Acid Metabolism

So far, over 50 spontaneous male sterile mutants of tomato have been described and most of them are categorized as genetic male sterility. To date, the mechanism of tomato genetic male sterility remained unclear. In this study, differential proteomic analysis is performed between genetic male sterile line (2‐517), which carries the male sterility (ms10³⁵) gene, and its wild‐type (VF‐11) using isobaric tags for relative and absolute quantification‐based strategy. A total of 8272 proteins are quantified in the 2–517 and VF‐11 lines at the floral bud and florescence stages. These proteins are involved in different cellular and metabolic processes, which express obvious functional tendencies toward the hydroxylation of the ω‐carbon in fatty acids, the tricarboxylic acid cycle, the glycolytic, and pentose phosphate pathways. Based on the results, a protein network explaining the mechanisms of tomato genetic male sterility is proposed, finding the compromising fat acid metabolism may cause the male sterility. These results are confirmed by parallel reaction monitoring, quantitative Real‐time PCR (qRT‐PCR), and physiological assays. Taken together, these results provide new insights into the metabolic pathway of anther abortion induced by ms10³⁵ and offer useful clues to identify the crucial proteins involved in genetic male sterility in tomato.     

AVPR1A variation is linked to gray matter covariation in the social brain network of chimpanzees

The vasopressin system has been implicated in the regulation of social behavior and cognition in humans, nonhuman primates and other social mammals. In chimpanzees, polymorphisms in the vasopressin V1a receptor gene (AVPR1A) have been associated with social dimensions of personality, as well as to responses to sociocommunicative cues and mirror self‐recognition. Despite evidence of this association with social cognition and behavior, there is little research on the neuroanatomical correlates of AVPR1A variation. In the current study, we tested the association between AVPR1A polymorphisms in the RS3 promotor region and gray matter covariation in chimpanzees using magnetic resonance imaging and source‐based morphometry. The analysis identified 13 independent brain components, three of which differed significantly in covariation between the two AVPR1A genotypes (DupB?/? and DupB+/?; P < .05). DupB+/? chimpanzees showed greater covariation in gray matter in the premotor and prefrontal cortex, basal forebrain, lunate and cingulate cortex, and lesser gray matter covariation in the superior temporal sulcus and postcentral sulcus. Some of these regions were previously found to differ in vasopressin and oxytocin neural fibers between nonhuman primates, and in AVPR1A gene expression in humans with different RS3 alleles. This is the first report of an association between AVPR1A and gray matter covariation in nonhuman primates, and specifically links an AVPR1A polymorphism to structural variation in the social brain network. These results further affirm the value of chimpanzees as a model species for investigating the relationship between genetic variation, brain structure and social cognition with relevance to psychiatric disorders, including autism.     

A single amino acid substitution in the movement protein enables the mechanical transmission of a geminivirus

Begomoviruses of the Geminiviridae are usually transmitted by whiteflies and rarely by mechanical inoculation. We used tomato leaf curl New Delhi virus (ToLCNDV), a bipartite begomovirus, to address this issue. Most ToLCNDV isolates are not mechanically transmissible to their natural hosts. The ToLCNDV-OM isolate, originally identified from a diseased oriental melon plant, is mechanically transmissible, while the ToLCNDV-CB isolate, from a diseased cucumber plant, is not. Genetic swapping and pathological tests were performed to identify the molecular determinants involved in mechanical transmission. Various viral infectious clones were constructed and successfully introduced into Nicotiana benthamiana, oriental melon, and cucumber plants by Agrobacterium-mediated inoculation. Mechanical transmissibility was assessed via direct rub inoculation with sap prepared from infected N. benthamiana. The presence or absence of viral DNA in plants was validated by PCR, Southern blotting, and in situ hybridization. The results reveal that mechanical transmissibility is associated with the movement protein (MP) of viral DNA-B in ToLCNDV-OM. However, the nuclear shuttle protein of DNA-B plays no role in mechanical transmission. Analyses of infectious clones carrying a single amino acid substitution reveal that the glutamate at amino acid position 19 of MP in ToLCNDV-OM is critical for mechanical transmissibility. The substitution of glutamate with glycine at this position in the MP of ToLCNDV-OM abolishes mechanical transmissibility. In contrast, the substitution of glycine with glutamate at the 19th amino acid position in the MP of ToLCNDV-CB enables mechanical transmission. This is the first time that a specific geminiviral movement protein has been identified as a determinant of mechanical transmissibility.