Ultra Low-Dose Radiation: Stress Responses and Impacts Using Rice as a Grass Model

We report molecular changes in leaves of rice plants (Oryza sativa L. - reference crop plant and grass model) exposed to ultra low-dose ionizing radiation, first using contaminated soil from the exclusion zone around Chernobyl reactor site. Results revealed induction of stress-related marker genes (Northern blot) and secondary metabolites (LC-MS/MS) in irradiated leaf segments over appropriate control. Second, employing the same in vitro model system, we replicated results of the first experiment using in-house fabricated sources of ultra low-dose gamma (γ) rays and selected marker genes by RT-PCR. Results suggest the usefulness of the rice model in studying ultra low-dose radiation response/s

Conversion of airborne nerolidol to DMNT emission requires additional signals in Achyranthes bidentata

AbstractDMNT biosynthesis was proposed to proceed via (E)-nerolidol in plants a decade ago. However, (E)-nerolidol function as airborne signal/substrate for in-vivo biosynthesis of DMNT remains to be investigated and the regulation of DMNT production and emission is largely unknown. We address both of these aspects using Achyranthes bidentata model plant in conjunction with deuterium-labeled d5-(E)-nerolidol, headspace, GC-FID, and GC/MS-based absolute quantification approaches. We demonstrate that airborne (E)-nerolidol is specifically metabolized in-vivo into DMNT emission, but requires airborne VOC MeJA or predator herbivore as additional environmental signal. In addition, we provide new insight into the complex regulation underlying DMNT emission, and highlight the importance of studying multiple environmental factors on emission patterns of plant VOCs and their mechanistic regulation

Phenylacetonitrile from the Giant Knotweed, Fallopia sachalinensis, Infested by the Japanese Beetle, Popillia japonica, Is Induced by Exogenous Methyl Jasmonate

Phenylacetonitrile, (E)-b-ocimene, linalool, (E)-4,8-dimethyl-1,3,7-nonatriene and (E,E)-a-farnesene were identified as Japanese beetle, Popillia japonica, feeding-induced volatiles from the leaves of the giant knotweed, Fallopia sachalinensis, but not by mechanical damage. Volatile emission was also induced by treatment with a cellular signaling molecule, methyl jasmonate. These results suggest that volatiles will be synthesized de novo by a biotic elicitor from P. japonica oral secretion

Isovaleronitrile co-induced with its precursor, l-leucine, by herbivory in the common evening primrose stimulates foraging behavior of the predatory blue shield bug

<p>Herbivore-induced plant volatiles play important roles in plant–insect and plant–plant interactions. The common evening primrose, <i>Oenothera biennis</i>, is often infested by the flea beetle, <i>Altica oleracea</i>, on which the predatory blue shield bug, <i>Zicrona caerulea</i>, is usually found. This observation suggests that the predatory bug can discriminate infested plants from intact ones to locate its prey. In this study, l-leucine-derived nitrogen-containing compounds [isovaleronitrile (3-methylbutanenitrile), (<i>E</i>/<i>Z</i>)-isovaleraldoxime and 3-methyl-1-nitrobutane] and some terpenes were identified as a characteristic volatile blend from herbivore-infested <i>O</i>. <i>biennis</i> leaves by gas chromatography/mass spectrometry, chemical synthesis, and incorporation assays using deuterium-labeled l-leucine. Volatile emission was also elicited by exogenous methyl jasmonate (MeJA), but not by mechanical damage. l-Leucine accumulated temporarily in <i>O</i>. <i>biennis</i> leaves after MeJA treatment prior to isovaleronitrile emission. Behavioral assays revealed that <i>Z</i>. <i>caerulea</i> showed a strong preference for herbivore-infested leaves, their volatiles, and isovaleronitrile in laboratory conditions.</p> <p>Herbivore-induced volatiles, including l-Leu-derived isovaleronitrile, from Oenothera biennis leaves elicit foraging behavior of a predator, Zicrona caerulea.</p

An Evaluation Model for the Quality of Frying Oil Using Key Aldehyde Detected by HS-GC/MS

To establish a practical model for evaluating the oxidation of frying oil using aldehydes, the aldehydes of 10 commercial oils during frying at 180 °C were identified using headspace-gas chromatography/mass spectrometry, and the changes of common aldehydes and their correlation with carbonyl values (CV) were analyzed. The results showed that the total peak area of aldehydes increased significantly with heating time, which was related to the fatty acid and tocopherol contents of the oils. There were four common aldehydes with different trends during frying, namely, pentanal, hexanal, (E)-hept-2-enal, and nonanal. Moreover, pentanal with a high correlation with CV was selected as the quality evaluating index of frying oil due to its stable accumulation over time. Based on the linear fitting relationships between CV and pentanal, as well as the initial content ratio of linoleic acid to palmitic acid and total tocopherols in oils, a predictive model was established for evaluating the quality of frying oils with high precision and non-reagent by using mass spectrometry. In summary, this work provides theoretical support for using aldehyde as the quality evaluation index of frying oil and provides a new idea for evaluating oil deterioration from the perspective of volatile compounds

Screening for γ-Nonalactone in the Headspace of Freshly Cooked Non-Scented Rice Using SPME/GC-O and SPME/GC-MS

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