Agronomic practices affect soil phosphorus(P) availability, P uptake by plants, and subsequently the efficiency of P use. A field experiment was carried out to investigate the effects of various agronomic practices(st...Agronomic practices affect soil phosphorus(P) availability, P uptake by plants, and subsequently the efficiency of P use. A field experiment was carried out to investigate the effects of various agronomic practices(straw incorporation, paddy water management, nitrogen(N) fertilizer dose, manure application,and biochar addition) on soil P availability(e.g., soil total P(STP), soil available P(SAP), soil microbial biomass P(SMBP), and rice P uptake as well as P use efficiency(PUE)) over four cropping seasons in a rice-rice cropping system, in subtropical central China. Compared to the non-straw treatment(control,using full dose of chemical N fertilizer), straw incorporation increased SAP and SMBP by 9.3%–18.5% and 15.5%–35.4%, respectively;substituting half the chemical N fertilizer dose with pig manure and the biochar application increased STP, SAP, and SMBP by 10.5%–48.3%, 30.2%–236.0%, and 19.8%–72.4%,respectively, mainly owing to increased soil P and organic carbon inputs;adding a half dose of N and no N input(reduced N treatments) increased STP and SAP by 2.6%–7.5% and 19.8%–33.7%, respectively, due to decreased soil P outputs. Thus, soil P availability was greatly affected by soil P input and use. The continuous flooding water regime without straw addition significantly decreased SMBP by 11.4% compared to corresponding treatments under a mid-season drainage water regime. Total P uptake by rice grains and straws at the harvest stage increased under straw incorporation and under pig manure application, but decreased under the reduced N treatments and under biochar application at a rate of 48 t ha-1, compared to the control. Rice P uptake was significantly positively correlated with rice biomass, and both were positively correlated with N fertilizer application rates, SAP, SMBP, and STP. Phosphorus use efficiency generally increased under straw incorporation but decreased under the reduced N treatments and under the manure application(with excessive P input), compared to the control. These results showed that straw incorporation can be used to increase soil P availability and PUE while decreasing the use of chemical P fertilizers. When substituting chemical fertilizers with pig manure, excess P inputs should be avoided in order to reduce P accumulation in the soil as well as the environmental risks from non-point source pollution.展开更多
The subtropical hilly region of China is a region with intensive crop and livestock production,which has resulted in serious N pollution in soil,water and air.This review summarizes the major soil N cycling processes ...The subtropical hilly region of China is a region with intensive crop and livestock production,which has resulted in serious N pollution in soil,water and air.This review summarizes the major soil N cycling processes and their influencing factors in rice paddies and uplands in the subtropical hilly region of China.The major N cycling processes include the N fertilizer application in croplands,atmospheric N deposition,biological N fixation,crop N uptake,ammonia volatilization,N_(2)O/NO emissions,nitrogen runoff and leaching losses.The catchment nutrients management model for N cycle modeling and its case studies in the subtropical hilly region were also introduced.Finally,N management practices for improving N use efficiency in cropland,as well as catchment scales are summarized.展开更多
Carotenoids constitute a large group of natural pigments widely distributed in nature.These compounds not only provide fruits and flowers with distinctive colors,but also have significant health benefits for humans.Lu...Carotenoids constitute a large group of natural pigments widely distributed in nature.These compounds not only provide fruits and flowers with distinctive colors,but also have significant health benefits for humans.Lutein and zeaxanthin,both oxygen-containing carotenoids,are considered to play vital roles in promoting ocular development and maintaining eye health.However,humans and mammals cannot synthesize these carotenoid derivatives,which can only be taken from certain fruits or vegetables.Here,by introducing four endogenous synthetic genes,SlLCYE,SlLCYB,SlHYDB,and SlHYDE under fruit-specific promoters,we report the metabolic engineering of lutein/zeaxanthin biosynthesis in tomato fruit.Transgenic lines overexpression of one(SlLCYE),two(SlLCYE and SlLCYB;SlLCYB and SlHYDB),and all these four synthetic genes re-established the lutein/zeaxanthin biosynthetic pathways in the ripe tomato fruit and thus resulted in various types of carotenoid riched lines.Metabolic analyses of these engineered tomato fruits showed the strategy involved expression of SlLCYE tends to produceα-carotene and lutein,as well as a higher content of β-carotene and zeaxanthin was detected in lines overexpressing SlLCYB.In addition,the different combinations of engineered tomatoes with riched carotenoids showed higher antioxidant capacity and were associated with a significantly extended shelf life during postharvest storage.This work provides a successful example of accurate metabolic engineering in tomato fruit,suggesting the potential utility for synthetic biology to improve agronomic traits in crops.These biofortified tomato fruits could be also exploited as new research subjects for studying the health benefits of carotenoid derivatives.展开更多
基金supported by the National Key Research and Development Program of China (Nos. 2016YFD0200307 and 2018YFC0213302)the Youth Innovation Promotion Association of Chinese Academy of Sciences (No. 2017418)。
文摘Agronomic practices affect soil phosphorus(P) availability, P uptake by plants, and subsequently the efficiency of P use. A field experiment was carried out to investigate the effects of various agronomic practices(straw incorporation, paddy water management, nitrogen(N) fertilizer dose, manure application,and biochar addition) on soil P availability(e.g., soil total P(STP), soil available P(SAP), soil microbial biomass P(SMBP), and rice P uptake as well as P use efficiency(PUE)) over four cropping seasons in a rice-rice cropping system, in subtropical central China. Compared to the non-straw treatment(control,using full dose of chemical N fertilizer), straw incorporation increased SAP and SMBP by 9.3%–18.5% and 15.5%–35.4%, respectively;substituting half the chemical N fertilizer dose with pig manure and the biochar application increased STP, SAP, and SMBP by 10.5%–48.3%, 30.2%–236.0%, and 19.8%–72.4%,respectively, mainly owing to increased soil P and organic carbon inputs;adding a half dose of N and no N input(reduced N treatments) increased STP and SAP by 2.6%–7.5% and 19.8%–33.7%, respectively, due to decreased soil P outputs. Thus, soil P availability was greatly affected by soil P input and use. The continuous flooding water regime without straw addition significantly decreased SMBP by 11.4% compared to corresponding treatments under a mid-season drainage water regime. Total P uptake by rice grains and straws at the harvest stage increased under straw incorporation and under pig manure application, but decreased under the reduced N treatments and under biochar application at a rate of 48 t ha-1, compared to the control. Rice P uptake was significantly positively correlated with rice biomass, and both were positively correlated with N fertilizer application rates, SAP, SMBP, and STP. Phosphorus use efficiency generally increased under straw incorporation but decreased under the reduced N treatments and under the manure application(with excessive P input), compared to the control. These results showed that straw incorporation can be used to increase soil P availability and PUE while decreasing the use of chemical P fertilizers. When substituting chemical fertilizers with pig manure, excess P inputs should be avoided in order to reduce P accumulation in the soil as well as the environmental risks from non-point source pollution.
基金supported by the National Natural Science Foundation of China(41771336,41471267,4211101081,42161144002)Youth Innovation Promotion Association of the Chinese Academy of Sciences(Y2021102)+1 种基金Key Research and Development Program of Hunan Province(2020NK2011)Chinese Academy of Science and Technology Service Network Initiative Project(KFJ-STSQYZD-2021-22-002).
文摘The subtropical hilly region of China is a region with intensive crop and livestock production,which has resulted in serious N pollution in soil,water and air.This review summarizes the major soil N cycling processes and their influencing factors in rice paddies and uplands in the subtropical hilly region of China.The major N cycling processes include the N fertilizer application in croplands,atmospheric N deposition,biological N fixation,crop N uptake,ammonia volatilization,N_(2)O/NO emissions,nitrogen runoff and leaching losses.The catchment nutrients management model for N cycle modeling and its case studies in the subtropical hilly region were also introduced.Finally,N management practices for improving N use efficiency in cropland,as well as catchment scales are summarized.
基金This study was funded by the National Natural Science Foundation of China(32170266)the Institutional Research Fund of Sichuan University(2020SCUNL106)the Fundamental Research Funds for the Central Universities(SCU2022D003).
文摘Carotenoids constitute a large group of natural pigments widely distributed in nature.These compounds not only provide fruits and flowers with distinctive colors,but also have significant health benefits for humans.Lutein and zeaxanthin,both oxygen-containing carotenoids,are considered to play vital roles in promoting ocular development and maintaining eye health.However,humans and mammals cannot synthesize these carotenoid derivatives,which can only be taken from certain fruits or vegetables.Here,by introducing four endogenous synthetic genes,SlLCYE,SlLCYB,SlHYDB,and SlHYDE under fruit-specific promoters,we report the metabolic engineering of lutein/zeaxanthin biosynthesis in tomato fruit.Transgenic lines overexpression of one(SlLCYE),two(SlLCYE and SlLCYB;SlLCYB and SlHYDB),and all these four synthetic genes re-established the lutein/zeaxanthin biosynthetic pathways in the ripe tomato fruit and thus resulted in various types of carotenoid riched lines.Metabolic analyses of these engineered tomato fruits showed the strategy involved expression of SlLCYE tends to produceα-carotene and lutein,as well as a higher content of β-carotene and zeaxanthin was detected in lines overexpressing SlLCYB.In addition,the different combinations of engineered tomatoes with riched carotenoids showed higher antioxidant capacity and were associated with a significantly extended shelf life during postharvest storage.This work provides a successful example of accurate metabolic engineering in tomato fruit,suggesting the potential utility for synthetic biology to improve agronomic traits in crops.These biofortified tomato fruits could be also exploited as new research subjects for studying the health benefits of carotenoid derivatives.