Fruit aroma of Guoqing 1, Miyagawa Wase, and Owari from three different Satsuma mandarin varieties were investigated by headspace solid phase microextraction （HS-SPME） combined with GC-MS. The results showed that th...Fruit aroma of Guoqing 1, Miyagawa Wase, and Owari from three different Satsuma mandarin varieties were investigated by headspace solid phase microextraction （HS-SPME） combined with GC-MS. The results showed that there were 73, 71, and 66 aroma components in the three varieties, and the total contents were 584.67,505.29, and 494.63 μg g^-1, respectively. Total 29 constituents were common in the three varieties. It was also found that Guoqing 1, Miyagawa Wase, and Owari had 12, 5, and 2 unique components, respectively. The key aroma components were limonene, linalool, γ-terpinene, β- myrcene, α-pinene, and octanal in the three fruits. Guoqing 1 contained more key aroma compounds than Miyagawa Wase and Owari.展开更多
Ethylene treatment promotes orange coloration in the flavedo of Satsuma mandarin(Citrus unshiu Marc.)fruit,but the corresponding regulatory mechanism is still largely unknown.In this study,we identified a C2H2-type zi...Ethylene treatment promotes orange coloration in the flavedo of Satsuma mandarin(Citrus unshiu Marc.)fruit,but the corresponding regulatory mechanism is still largely unknown.In this study,we identified a C2H2-type zinc-finger transcription factor,CitZAT4,the expression of which was markedly induced by ethylene.CitZAT4 directly binds to the Cit PSY promoter and activates its expression,thereby promoting carotenoid biosynthesis.Transient expression in Satsuma mandarin fruit and stable transformation of citrus calli showed that overexpressing of CitZAT4 inhibited Cit LCYE expression,thus inhibitingα-branch yellow carotenoid(lutein)biosynthesis.CitZAT4 overexpression also enhanced the transcript levels of CitLCYB,Cit HYD,and CitNCED2,promotingβ-branch orange carotenoid accumulation.Molecular biochemical assays,including yeast one-hybrid(Y1H),electrophoretic mobility shift(EMSA),chromatin immunoprecipitation quantitative polymerase chain reaction(Ch IP-q PCR),and luciferase(LUC)assays,demonstrated that CitZAT4 directly binds to the promoters of its target genes and regulates their expression.An ethylene response factor,CitERF061,which is induced by ethylene signaling,was found to directly bound to the CitZAT4 promoter and induced its expression,thus positively regulating CitZAT4-mediated orange coloration in citrus fruit.Together,our findings reveal that a CitZAT4-mediated transcriptional cascade is driven by ethylene via CitERF061,linking ethylene signaling to carotenoid metabolism in promoting orange coloration in the flavedo of Satsuma mandarin fruit.The molecular regulatory mechanism revealed here represents a significant step toward developing strategies for improving the quality and economic efficiency of citrus crops.展开更多
Present study introduced a controlled freezing-point storage(CFPS)technique for the postharvest storage of satsuma mandarin(Citrus unshiu Marc.cv.Miyagawa Wase),with the environment temperature of−2℃ during the whole...Present study introduced a controlled freezing-point storage(CFPS)technique for the postharvest storage of satsuma mandarin(Citrus unshiu Marc.cv.Miyagawa Wase),with the environment temperature of−2℃ during the whole storage period.The postharvest loss and quality changes of satsuma mandarin were investigated.according to the results,CFPS completely prevented fruit decay in the 90 days storage and the following shelf period without causing fruit chilling injury.in comparison,the decay rate of fruit stored at 10℃ increased with the elongation of storage time,and reach to 6.67%after 90 days storage,then further increased to 33.33%after transferring to the shelf.CFPS significantly reduced the incidences of calyx browning,completely prevented fruit puffing,alleviated the decreases of citric acid,fructose and glucose in the long-term storage and the following shelf life of satsuma mandarin,compared with the 10℃ storage.but CFPS alleviated the postharvest rind color development of satsuma mandarin,leading to paler rind color compared to the 10℃ storage group.both 10℃ storage and CFPS group showed significant decrease of total aroma volatiles contents in the pulp after more than two months’storage.but most of the volatiles,including all of the monoterpenes and aliphatic alcohols,as well as part of the monoterpenes derivatives and aliphatic aldehydes,rebound after being transferred to the 20℃ shelf,with the extent much higher in 10℃ storage group than that in CFPS group.in the shelf-life,the total volatile content of the 10℃ storage group was about 2 fold that of the newly-harvested fruit,but the volatiles of the CFPS group were more similar to the newly-harvested fruit in content and composition.Correspondingly,the consumer’s sensory evaluation results showed that the fruit of CFPS group was slightly sourer and with better typical mandarin flavor than those stored at 10℃.Comprehensively,CFPS was applicable in reducing the postharvest loss and alleviating quality deterioration in the long-term storage of satsuma mandarin.展开更多
Dynamics of dry- or fresh-weight of fruit, peel photosynthetic rate and chlorophyll content, and the characteristics of translocation and distribution of radiolabelled assimilates from leaf or fruit were examined in d...Dynamics of dry- or fresh-weight of fruit, peel photosynthetic rate and chlorophyll content, and the characteristics of translocation and distribution of radiolabelled assimilates from leaf or fruit were examined in developing satsuma mandarin (Citrus unshiu Marc. cv. Miyagawa wase) fruit from primary stage of fruit enlargement up to fruit full ripe. Change in fruit photosynthetic rate was some what related to the change in the chlorophyll content of peel. Fruit photosynthetic rate markedly declined as chlorophyll degradation occurred in the peel. Before full ripe stage of the fruit, photosynthates produced by a 14C-fed leaf were mainly distributed to juice sacs even during periods when dry matter accumulation in peel was more rapid than that in juice sacs. At the full ripe stage, peel photosynthetic rate approached zero and peel became the major sink of leaf photosynthates. Most of the peel assimilates, however, remained in situ for up to 48 h after feeding 14CO 2 to the fruit, only a small portion being transported to other parts of fruit. The percentage of fruit photosynthates exported decreased with fruit development and ripening, but the peak rate of export to juice sacs amount to as high as 12%. The sugar content and dry weights of peel and juice sacs in shaded fruit were lower than that in the control fruit. These results show that peel assimilate was mainly consumed in peel respiration and growth and thus the dependence on leaf photosynthates decreased. Part of this assimiate was used in sugar accumulation in juice sacs of fruit.展开更多
文摘Fruit aroma of Guoqing 1, Miyagawa Wase, and Owari from three different Satsuma mandarin varieties were investigated by headspace solid phase microextraction （HS-SPME） combined with GC-MS. The results showed that there were 73, 71, and 66 aroma components in the three varieties, and the total contents were 584.67,505.29, and 494.63 μg g^-1, respectively. Total 29 constituents were common in the three varieties. It was also found that Guoqing 1, Miyagawa Wase, and Owari had 12, 5, and 2 unique components, respectively. The key aroma components were limonene, linalool, γ-terpinene, β- myrcene, α-pinene, and octanal in the three fruits. Guoqing 1 contained more key aroma compounds than Miyagawa Wase and Owari.
基金supported by the National Key R&D Program of China(2023YFD2300600)the National Natural Science Foundation of China(No.31930095)the National Modern Agricultural(Citrus)Technology Systems of China(No.CARS-27)。
文摘Ethylene treatment promotes orange coloration in the flavedo of Satsuma mandarin(Citrus unshiu Marc.)fruit,but the corresponding regulatory mechanism is still largely unknown.In this study,we identified a C2H2-type zinc-finger transcription factor,CitZAT4,the expression of which was markedly induced by ethylene.CitZAT4 directly binds to the Cit PSY promoter and activates its expression,thereby promoting carotenoid biosynthesis.Transient expression in Satsuma mandarin fruit and stable transformation of citrus calli showed that overexpressing of CitZAT4 inhibited Cit LCYE expression,thus inhibitingα-branch yellow carotenoid(lutein)biosynthesis.CitZAT4 overexpression also enhanced the transcript levels of CitLCYB,Cit HYD,and CitNCED2,promotingβ-branch orange carotenoid accumulation.Molecular biochemical assays,including yeast one-hybrid(Y1H),electrophoretic mobility shift(EMSA),chromatin immunoprecipitation quantitative polymerase chain reaction(Ch IP-q PCR),and luciferase(LUC)assays,demonstrated that CitZAT4 directly binds to the promoters of its target genes and regulates their expression.An ethylene response factor,CitERF061,which is induced by ethylene signaling,was found to directly bound to the CitZAT4 promoter and induced its expression,thus positively regulating CitZAT4-mediated orange coloration in citrus fruit.Together,our findings reveal that a CitZAT4-mediated transcriptional cascade is driven by ethylene via CitERF061,linking ethylene signaling to carotenoid metabolism in promoting orange coloration in the flavedo of Satsuma mandarin fruit.The molecular regulatory mechanism revealed here represents a significant step toward developing strategies for improving the quality and economic efficiency of citrus crops.
基金supported by the Key Research and Development Projects of Zhejiang Province(2021C02015)Fundamental Research Funds for the Central Universities(226-2022-00215)Science and Technology Innovation Team of the Ministry of Agriculture and Rural Affairs.
文摘Present study introduced a controlled freezing-point storage(CFPS)technique for the postharvest storage of satsuma mandarin(Citrus unshiu Marc.cv.Miyagawa Wase),with the environment temperature of−2℃ during the whole storage period.The postharvest loss and quality changes of satsuma mandarin were investigated.according to the results,CFPS completely prevented fruit decay in the 90 days storage and the following shelf period without causing fruit chilling injury.in comparison,the decay rate of fruit stored at 10℃ increased with the elongation of storage time,and reach to 6.67%after 90 days storage,then further increased to 33.33%after transferring to the shelf.CFPS significantly reduced the incidences of calyx browning,completely prevented fruit puffing,alleviated the decreases of citric acid,fructose and glucose in the long-term storage and the following shelf life of satsuma mandarin,compared with the 10℃ storage.but CFPS alleviated the postharvest rind color development of satsuma mandarin,leading to paler rind color compared to the 10℃ storage group.both 10℃ storage and CFPS group showed significant decrease of total aroma volatiles contents in the pulp after more than two months’storage.but most of the volatiles,including all of the monoterpenes and aliphatic alcohols,as well as part of the monoterpenes derivatives and aliphatic aldehydes,rebound after being transferred to the 20℃ shelf,with the extent much higher in 10℃ storage group than that in CFPS group.in the shelf-life,the total volatile content of the 10℃ storage group was about 2 fold that of the newly-harvested fruit,but the volatiles of the CFPS group were more similar to the newly-harvested fruit in content and composition.Correspondingly,the consumer’s sensory evaluation results showed that the fruit of CFPS group was slightly sourer and with better typical mandarin flavor than those stored at 10℃.Comprehensively,CFPS was applicable in reducing the postharvest loss and alleviating quality deterioration in the long-term storage of satsuma mandarin.
文摘Dynamics of dry- or fresh-weight of fruit, peel photosynthetic rate and chlorophyll content, and the characteristics of translocation and distribution of radiolabelled assimilates from leaf or fruit were examined in developing satsuma mandarin (Citrus unshiu Marc. cv. Miyagawa wase) fruit from primary stage of fruit enlargement up to fruit full ripe. Change in fruit photosynthetic rate was some what related to the change in the chlorophyll content of peel. Fruit photosynthetic rate markedly declined as chlorophyll degradation occurred in the peel. Before full ripe stage of the fruit, photosynthates produced by a 14C-fed leaf were mainly distributed to juice sacs even during periods when dry matter accumulation in peel was more rapid than that in juice sacs. At the full ripe stage, peel photosynthetic rate approached zero and peel became the major sink of leaf photosynthates. Most of the peel assimilates, however, remained in situ for up to 48 h after feeding 14CO 2 to the fruit, only a small portion being transported to other parts of fruit. The percentage of fruit photosynthates exported decreased with fruit development and ripening, but the peak rate of export to juice sacs amount to as high as 12%. The sugar content and dry weights of peel and juice sacs in shaded fruit were lower than that in the control fruit. These results show that peel assimilate was mainly consumed in peel respiration and growth and thus the dependence on leaf photosynthates decreased. Part of this assimiate was used in sugar accumulation in juice sacs of fruit.
