The juvenile-to-adult phase change with first flowering as the indicator plays a crucial role in the lifecycle of fruit trees. However, the molecular mechanisms underlying phase change in fruit trees remain largely un...The juvenile-to-adult phase change with first flowering as the indicator plays a crucial role in the lifecycle of fruit trees. However, the molecular mechanisms underlying phase change in fruit trees remain largely unknown. Shikimic acid (ShA) pathway is a main metabolic pathway closely related to the synthesis of hormones and many important secondary metabolites participating in plant phase change. So,whether ShA regulates phase change in plants is worth clarifying. Here, the distinct morphological characteristics and the underlying mechanisms of phase change in jujube (Ziziphus jujuba Mill.), an important fruit tree native to China with nutritious fruit and outstanding tolerance abiotic stresses, were clarified. A combined transcriptome and metabolome analysis found that ShA is positively involved in jujube(Yuhong’×Xing 16’) phase change. The genes in the upstream of ShA synthesis pathway (ZjDAHPS, ZjDHQS and ZjSDH), the contents of ShA and the downstream secondary metabolites like phenols were significantly upregulated in the phase change period. Further, the treatment of spraying exogenous ShA verified that ShA at a very low concentration (60 mg·L^(-1)) can substantially speed up the phase change and flowering of jujube and other tested plants including Arabidopsis, tomato and wheat. The exogenous ShA (60 mg·L^(-1)) treatment in jujube seedlings could increase the accumulation of endogenous ShA, enhance leaf photosynthesis and the synthesis of phenols especially flavonoids and phenolic acids, and promote the expression of genes (ZjCOs, ZjNFYs and ZjPHYs) involved in flowering pathway. Basing on above results, we put forward a propose for the underlying mechanism of ShA regulating phase change, and a hypothesis that ShA could be considered a phytohormone-like substance because it is endogenous, ubiquitous, movable and highly efficient at very low concentrations. This study highlights the critical role of ShA in plant phase change and its phytohormone-like properties.展开更多
The effects of Roundup </span><span><span style="font-family:Verdana;">WeatherMax</span><sup><span style="font-family:Verdana;"><sup>®</sup>&...The effects of Roundup </span><span><span style="font-family:Verdana;">WeatherMax</span><sup><span style="font-family:Verdana;"><sup>®</sup></span></sup></span></span><span><span><span style="font-family:Verdana;"> and </span><span style="font-family:Verdana;">Engame<sup>TM</sup></span></span></span><span><span><span style="font-family:Verdana;"> formulations of glyphosate were investigated on the cotyledons of glyphosate resistant (GR) and glyphosate sensitive (GS) isogenic cotton cultivars. </span><span style="font-family:Verdana;">Engame<sup>TM</sup></span></span></span><span><span><span style="font-family:Verdana;"> is a mixture of glyphosate and 1-aminomethanamide dihydrogen tetraoxosulfate (AMADS). Fully expanded cotton cotyledons treated with </span><span style="font-family:Verdana;">Engame<sup>TM</sup></span></span></span><span><span><span style="font-family:Verdana;"> or AMADS developed surface lesions within 2 hours after treatment whereas surfactant-treated control or </span><span><span style="font-family:Verdana;">WeatherMax</span><sup><span style="font-family:Verdana;"><sup>®</sup></span></sup></span></span></span><span><span><span style="font-family:Verdana;">-treated tissues did not develop lesions. The </span><span style="font-family:Verdana;">Engame<sup>TM</sup></span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;"> and AMADS damage appeared as depressions which were confirmed </span><span style="font-family:Verdana;">by scanning electron microscopy. Light micrographs of cross sections</span><span style="font-family:Verdana;"> through the depressions revealed collapsed and compressed epidermal and mesophyll cells with congealed cytoplasmic contents in the palisade and spongy mesophyll cells. Changes to photosynthetic electron transport were evident at 4 hours after treatment (HAT) in all treatments as revealed by chlorophyll A fluorescence. In GR cotton, the fluorescence perturbations decreased with time such that at 72 HAT </span></span><span style="font-family:Verdana;">Engame<sup>TM</sup></span></span></span><span><span><span style="font-family:Verdana;">-treated cotyledons could not be distinguished from the surfactant-or </span><span><span style="font-family:Verdana;">WeatherMax</span><sup><span style="font-family:Verdana;"><sup>®</sup></span></sup></span></span></span><span><span><span style="font-family:Verdana;">-treated plants. The GS cotton continued to show progressive decreases in the fluorescence parameters Fv/Fm and performance index (PI) to 72 HAT. Shikimate levels increased following glyphosate treatment in glyphosate sensitive cotton and </span><span style="font-family:Verdana;">Engame<sup>TM</sup></span></span></span><span><span><span style="font-family:Verdana;"> caused a two-to three-fold greater increase in shikimate compared to </span><span><span style="font-family:Verdana;">WeatherMax</span><sup><span style="font-family:Verdana;"><sup>®</sup></span></sup></span></span></span><span><span><span style="font-family:Verdana;">. These results indicate that the </span><span style="font-family:Verdana;">Engame<sup>TM</sup></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-based glyphosate formulation involved structural tissue damage which likely increased glyphosate uptake and subsequently increased inhibition of photosynthesis and the shikimate pathway.展开更多
Shikimic acid is a hydroaromatic compound possessing critical biological properties,such as antibacterial and antiviral activity.This review mainly focused on shikimic acid and its derivatives.We first briefly introdu...Shikimic acid is a hydroaromatic compound possessing critical biological properties,such as antibacterial and antiviral activity.This review mainly focused on shikimic acid and its derivatives.We first briefly introduced the sources of shikimic acid and its derivatives and discussed their biosynthesis.Several in vitro and in vivo studies indicate that shikimic acid and its derivatives exhibit diverse bioactivities,such as antioxidant,antiviral,anti-inflammatory,antibacterial,hypolipidemic,bone protective,skin protective,neuroprotective,and antidiabetic activities.We mainly focused on the related molecular mechanisms.Overall,the wide range of bioactivities of shikimic acid and its derivatives indicate that a more detailed exploration of their potential for the prevention and treatment of certain diseases is warranted.展开更多
(6S)-6-Fluoroshikimic acid 2 and (6 R ) 6 hydroxyshikimic acid 3 have been synthesized via an OsO 4 catalysed dihydroxylation of diene 7, which was derived from (-) shikimic acid 1.
基金partially supported by the National Natural Science Foundation of China (Grant No.31772285)the National Key R&D Program Project Funding (Grant No.2018YFD1000607)Foundation for 100 Innovative Talents of Hebei Province(Grant No.SLRC2019031)。
文摘The juvenile-to-adult phase change with first flowering as the indicator plays a crucial role in the lifecycle of fruit trees. However, the molecular mechanisms underlying phase change in fruit trees remain largely unknown. Shikimic acid (ShA) pathway is a main metabolic pathway closely related to the synthesis of hormones and many important secondary metabolites participating in plant phase change. So,whether ShA regulates phase change in plants is worth clarifying. Here, the distinct morphological characteristics and the underlying mechanisms of phase change in jujube (Ziziphus jujuba Mill.), an important fruit tree native to China with nutritious fruit and outstanding tolerance abiotic stresses, were clarified. A combined transcriptome and metabolome analysis found that ShA is positively involved in jujube(Yuhong’×Xing 16’) phase change. The genes in the upstream of ShA synthesis pathway (ZjDAHPS, ZjDHQS and ZjSDH), the contents of ShA and the downstream secondary metabolites like phenols were significantly upregulated in the phase change period. Further, the treatment of spraying exogenous ShA verified that ShA at a very low concentration (60 mg·L^(-1)) can substantially speed up the phase change and flowering of jujube and other tested plants including Arabidopsis, tomato and wheat. The exogenous ShA (60 mg·L^(-1)) treatment in jujube seedlings could increase the accumulation of endogenous ShA, enhance leaf photosynthesis and the synthesis of phenols especially flavonoids and phenolic acids, and promote the expression of genes (ZjCOs, ZjNFYs and ZjPHYs) involved in flowering pathway. Basing on above results, we put forward a propose for the underlying mechanism of ShA regulating phase change, and a hypothesis that ShA could be considered a phytohormone-like substance because it is endogenous, ubiquitous, movable and highly efficient at very low concentrations. This study highlights the critical role of ShA in plant phase change and its phytohormone-like properties.
文摘The effects of Roundup </span><span><span style="font-family:Verdana;">WeatherMax</span><sup><span style="font-family:Verdana;"><sup>®</sup></span></sup></span></span><span><span><span style="font-family:Verdana;"> and </span><span style="font-family:Verdana;">Engame<sup>TM</sup></span></span></span><span><span><span style="font-family:Verdana;"> formulations of glyphosate were investigated on the cotyledons of glyphosate resistant (GR) and glyphosate sensitive (GS) isogenic cotton cultivars. </span><span style="font-family:Verdana;">Engame<sup>TM</sup></span></span></span><span><span><span style="font-family:Verdana;"> is a mixture of glyphosate and 1-aminomethanamide dihydrogen tetraoxosulfate (AMADS). Fully expanded cotton cotyledons treated with </span><span style="font-family:Verdana;">Engame<sup>TM</sup></span></span></span><span><span><span style="font-family:Verdana;"> or AMADS developed surface lesions within 2 hours after treatment whereas surfactant-treated control or </span><span><span style="font-family:Verdana;">WeatherMax</span><sup><span style="font-family:Verdana;"><sup>®</sup></span></sup></span></span></span><span><span><span style="font-family:Verdana;">-treated tissues did not develop lesions. The </span><span style="font-family:Verdana;">Engame<sup>TM</sup></span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;"> and AMADS damage appeared as depressions which were confirmed </span><span style="font-family:Verdana;">by scanning electron microscopy. Light micrographs of cross sections</span><span style="font-family:Verdana;"> through the depressions revealed collapsed and compressed epidermal and mesophyll cells with congealed cytoplasmic contents in the palisade and spongy mesophyll cells. Changes to photosynthetic electron transport were evident at 4 hours after treatment (HAT) in all treatments as revealed by chlorophyll A fluorescence. In GR cotton, the fluorescence perturbations decreased with time such that at 72 HAT </span></span><span style="font-family:Verdana;">Engame<sup>TM</sup></span></span></span><span><span><span style="font-family:Verdana;">-treated cotyledons could not be distinguished from the surfactant-or </span><span><span style="font-family:Verdana;">WeatherMax</span><sup><span style="font-family:Verdana;"><sup>®</sup></span></sup></span></span></span><span><span><span style="font-family:Verdana;">-treated plants. The GS cotton continued to show progressive decreases in the fluorescence parameters Fv/Fm and performance index (PI) to 72 HAT. Shikimate levels increased following glyphosate treatment in glyphosate sensitive cotton and </span><span style="font-family:Verdana;">Engame<sup>TM</sup></span></span></span><span><span><span style="font-family:Verdana;"> caused a two-to three-fold greater increase in shikimate compared to </span><span><span style="font-family:Verdana;">WeatherMax</span><sup><span style="font-family:Verdana;"><sup>®</sup></span></sup></span></span></span><span><span><span style="font-family:Verdana;">. These results indicate that the </span><span style="font-family:Verdana;">Engame<sup>TM</sup></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-based glyphosate formulation involved structural tissue damage which likely increased glyphosate uptake and subsequently increased inhibition of photosynthesis and the shikimate pathway.
基金financial support from Rajagiri College of Social Sciences (Autonomous)Kochi+1 种基金Indiain the seed money category for minor faculty research projects
文摘Shikimic acid is a hydroaromatic compound possessing critical biological properties,such as antibacterial and antiviral activity.This review mainly focused on shikimic acid and its derivatives.We first briefly introduced the sources of shikimic acid and its derivatives and discussed their biosynthesis.Several in vitro and in vivo studies indicate that shikimic acid and its derivatives exhibit diverse bioactivities,such as antioxidant,antiviral,anti-inflammatory,antibacterial,hypolipidemic,bone protective,skin protective,neuroprotective,and antidiabetic activities.We mainly focused on the related molecular mechanisms.Overall,the wide range of bioactivities of shikimic acid and its derivatives indicate that a more detailed exploration of their potential for the prevention and treatment of certain diseases is warranted.
文摘(6S)-6-Fluoroshikimic acid 2 and (6 R ) 6 hydroxyshikimic acid 3 have been synthesized via an OsO 4 catalysed dihydroxylation of diene 7, which was derived from (-) shikimic acid 1.