Content variations of the four components in the plants of rice ASD7, IR36 （resistant to brown planthopper） and TN1 （susceptible to brown planthopper）, and their influence on rice resistance to brown planthopper ...Content variations of the four components in the plants of rice ASD7, IR36 （resistant to brown planthopper） and TN1 （susceptible to brown planthopper）, and their influence on rice resistance to brown planthopper （BPH, Nilaparvata lugens） were investigated. The resistance diversity of rice to BPH biotype II at different plant ages was chiefly attributed to the content variability of the secondary compounds. The contents in the leaf sheath were the lowest as compared with other parts of rice plant. It might explain the reason that BPH has a preference for feeding on leaf sheath aggregately from chemical point of view.展开更多
Fractionated carbazoles have been detected for the first time in crude oils from the Tazhong area of the Tarim Basin, and these nitrogen compounds were successfully utilized in the study of petroleum migration. Alkylc...Fractionated carbazoles have been detected for the first time in crude oils from the Tazhong area of the Tarim Basin, and these nitrogen compounds were successfully utilized in the study of petroleum migration. Alkylcarbazoles are quite abundant in all the samples analyzed; small amounts of benzocarbazoles were detected only in some of the samples, and dibenzocarbazoles were not found in the oils. Based on the distributions of G1, G2 and G3 types of C\-2\|alkylcarbazoles, the ratio of C\-3\|/C\-2\|carbazoles and the relative concentrations of alkylcarbazole and alkylbenzocarbazole, oils in the Carboniferous C\-Ⅲ reservoir in the Tazhong uplift are thought to have laterally migrated to the high level of Tazhong structure No. 4 from both northwest and southeast. The study here also shows that oils in the area may have undergone long\|distance migration.展开更多
The research, focused on the specific interactions among seven plant secondary compounds and aphids, was carried out and the preliminary results showed: (1) 'T-typed tube method' was regarded as the best metho...The research, focused on the specific interactions among seven plant secondary compounds and aphids, was carried out and the preliminary results showed: (1) 'T-typed tube method' was regarded as the best method compared with others designed to observe the interactions. (2) Cabbage aphid was able to be attracted by laurolene while it was not susceptible to α-pinene, β-pinene and diamylene. (3) Gossypol, a major secondary substance in cotton, was able to be implicated as feeding attractant to cotton aphid. (4) Rutin might be implicated repellent to cotton aphid.展开更多
Mono-substituted heterocyclic ketene aminals are formed by the reaction of 1-methyl-2-methylthio-imidazoline with active methylene compounds containinq an acetyl or benzoyl group by the elimination of both a methylthi...Mono-substituted heterocyclic ketene aminals are formed by the reaction of 1-methyl-2-methylthio-imidazoline with active methylene compounds containinq an acetyl or benzoyl group by the elimination of both a methylthio and an acyl group.This is resulted by the secondary reactio of the produced methanethiol to attack the more active carbonyl group.展开更多
Senescence is a natural, energy-dependent, physiological, developmental and an ecological process that is controlled by the plant’s own genetic program, allowing maximum recovery of nutrients from older organs for th...Senescence is a natural, energy-dependent, physiological, developmental and an ecological process that is controlled by the plant’s own genetic program, allowing maximum recovery of nutrients from older organs for the survival of the plant, as such;it is classified as essential component of the growth and development of plants. In some cases, under one or many environmental stresses, senescence is triggered in plants. Despite many studies in the area, less consideration has been given to plant secondary metabolites, especially the role of VTCs on plant senescence. This review seeks to capture the biosynthesis and signal transduction of VTCs, the physiology of VTCs in plant development and how that is linked to some phytohormones to induce senescence. Much progress has been made in the elucidation of metabolic pathways leading to the biosynthesis of VTCs. In addition to the classical cytosolic mevalonic acid (MVA) pathway from acetyl-CoA, the 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway, originating from glyceraldehyde-3-phosphate (GAP) and pyruvate, leads to the biosynthesis of isoprenoid precursors, isopentenyl diphosphate and dimethyl allyl diphosphate. VTCs synthesis and emission are believed to be tightly regulated by photosynthetic carbon supply into MEP pathway. Thus, under abiotic stresses such as drought, high salinity, high and low temperature, and low CO2 that directly affect stomatal conductance and ultimately biochemical limitation to photosynthesis, there has been observed induction of VTC synthesis and emissions, reflecting the elicitation of MEP pathway. This reveals the possibility of important function(s) of VTCs in plant defense against stress by mobilizing resources from components of plants and therefore, senescence. Our current understanding of the relationship between environmental responses and senescence mostly comes from the study of senescence response to phytohormones such as abscisic acid, jasmonic acid, ethylene and salicylic acid, which are extensively involved in response to various abiotic and biotic stresses. These stresses affect synthesis and/or signaling pathways of phytohormones to eventually trigger expression of stress-responsive genes, which in turn appears to affect leaf senescence. Comparison of plant response to stresses in relation to patterns of VTCs and phytohormones biosynthesis indicates a considerable crosstalk between these metabolic processes and their signal to plant senescence.展开更多
基金supported by the Key Program of National Natural Science Foundation of China(39930120)the President Research Grant of South China Agricultural University(2002047)
文摘Content variations of the four components in the plants of rice ASD7, IR36 （resistant to brown planthopper） and TN1 （susceptible to brown planthopper）, and their influence on rice resistance to brown planthopper （BPH, Nilaparvata lugens） were investigated. The resistance diversity of rice to BPH biotype II at different plant ages was chiefly attributed to the content variability of the secondary compounds. The contents in the leaf sheath were the lowest as compared with other parts of rice plant. It might explain the reason that BPH has a preference for feeding on leaf sheath aggregately from chemical point of view.
文摘Fractionated carbazoles have been detected for the first time in crude oils from the Tazhong area of the Tarim Basin, and these nitrogen compounds were successfully utilized in the study of petroleum migration. Alkylcarbazoles are quite abundant in all the samples analyzed; small amounts of benzocarbazoles were detected only in some of the samples, and dibenzocarbazoles were not found in the oils. Based on the distributions of G1, G2 and G3 types of C\-2\|alkylcarbazoles, the ratio of C\-3\|/C\-2\|carbazoles and the relative concentrations of alkylcarbazole and alkylbenzocarbazole, oils in the Carboniferous C\-Ⅲ reservoir in the Tazhong uplift are thought to have laterally migrated to the high level of Tazhong structure No. 4 from both northwest and southeast. The study here also shows that oils in the area may have undergone long\|distance migration.
文摘The research, focused on the specific interactions among seven plant secondary compounds and aphids, was carried out and the preliminary results showed: (1) 'T-typed tube method' was regarded as the best method compared with others designed to observe the interactions. (2) Cabbage aphid was able to be attracted by laurolene while it was not susceptible to α-pinene, β-pinene and diamylene. (3) Gossypol, a major secondary substance in cotton, was able to be implicated as feeding attractant to cotton aphid. (4) Rutin might be implicated repellent to cotton aphid.
文摘Mono-substituted heterocyclic ketene aminals are formed by the reaction of 1-methyl-2-methylthio-imidazoline with active methylene compounds containinq an acetyl or benzoyl group by the elimination of both a methylthio and an acyl group.This is resulted by the secondary reactio of the produced methanethiol to attack the more active carbonyl group.
文摘Senescence is a natural, energy-dependent, physiological, developmental and an ecological process that is controlled by the plant’s own genetic program, allowing maximum recovery of nutrients from older organs for the survival of the plant, as such;it is classified as essential component of the growth and development of plants. In some cases, under one or many environmental stresses, senescence is triggered in plants. Despite many studies in the area, less consideration has been given to plant secondary metabolites, especially the role of VTCs on plant senescence. This review seeks to capture the biosynthesis and signal transduction of VTCs, the physiology of VTCs in plant development and how that is linked to some phytohormones to induce senescence. Much progress has been made in the elucidation of metabolic pathways leading to the biosynthesis of VTCs. In addition to the classical cytosolic mevalonic acid (MVA) pathway from acetyl-CoA, the 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway, originating from glyceraldehyde-3-phosphate (GAP) and pyruvate, leads to the biosynthesis of isoprenoid precursors, isopentenyl diphosphate and dimethyl allyl diphosphate. VTCs synthesis and emission are believed to be tightly regulated by photosynthetic carbon supply into MEP pathway. Thus, under abiotic stresses such as drought, high salinity, high and low temperature, and low CO2 that directly affect stomatal conductance and ultimately biochemical limitation to photosynthesis, there has been observed induction of VTC synthesis and emissions, reflecting the elicitation of MEP pathway. This reveals the possibility of important function(s) of VTCs in plant defense against stress by mobilizing resources from components of plants and therefore, senescence. Our current understanding of the relationship between environmental responses and senescence mostly comes from the study of senescence response to phytohormones such as abscisic acid, jasmonic acid, ethylene and salicylic acid, which are extensively involved in response to various abiotic and biotic stresses. These stresses affect synthesis and/or signaling pathways of phytohormones to eventually trigger expression of stress-responsive genes, which in turn appears to affect leaf senescence. Comparison of plant response to stresses in relation to patterns of VTCs and phytohormones biosynthesis indicates a considerable crosstalk between these metabolic processes and their signal to plant senescence.
