Maize(Zea mays L.)is one of the world's most important staple crops,and is used for manufacturing food,feed,and industrial products.A key factor in maize yield is the grain weight,which directly influences product...Maize(Zea mays L.)is one of the world's most important staple crops,and is used for manufacturing food,feed,and industrial products.A key factor in maize yield is the grain weight,which directly influences productivity.In this study,we revealed the role of smk23 in maize kernel development.The ethyl methanesulfonate mutant smk23 is characterized by substantially reduced kernel weight.Through map-based cloning,smk23 was found to be located on Chr5 and encode a putative B-type response regulator,Zm RR5.A change from G to A occurs in the coding sequence of Zm RR5,resulting in the early termination of smk23.In Arabidopsis,B-type response regulators are involved in cytokinin signaling.Histological analysis and in situ hybridization of the mutant revealed abnormal endosperm development,particularly in the basal endosperm transfer layer(BETL),a specialized tissue critical for nutrient transport from the maternal tissues to the developing kernel.Zm RR5 positively regulates key genes involved in BETL development and function,including MRP1 and TCRR1.Furthermore,RNA sequencing revealed that several genes closely linked to BETL development,including BETL2,MEG1,and MN1,were significantly downregulated in smk23.These genes are essential for nutrient transport,tissue development and signal transduction.In addition,haploid analysis of Zm RR5 revealed natural variations(Hap 2)that may contribute to the increased kernel yield.Disruption of Zm RR5 function in smk23 leads to defects in BETL development,impairing its ability to transport nutrients,and ultimately resulting in a smaller kernel size.This study provides new insights into the molecular mechanisms through which Zm RR5 regulates maize kernel development and offers potential strategies for improving grain yield.展开更多
[Objective] This study aimed to make a survey of domestic pigeons for infection with Eimeria species of coccidia was conducted in Guangdong Province, southern China. [Method] A total of 244 fecal samples(102 from Huiz...[Objective] This study aimed to make a survey of domestic pigeons for infection with Eimeria species of coccidia was conducted in Guangdong Province, southern China. [Method] A total of 244 fecal samples(102 from Huizhou, 83 from Jiangmen, 35 from Chaozhou and 24 from Guangzhou, respectively) in four pigeon breeding farms between June 2012 and March2013 were collected and examined microscopically. [Results] Eimeria oocysts were seen in 223(91.4%) fecal samples, with three species, namely E. labbeana, E.columbae and E. kapotei. E. labbeana was the most common species in Guangdong provinces with an overall prevalence of 91.4%, while a slightly lower incidence of E. columbae and E. kapotei species was detected with11.1% and 6.6%, representatively. The prevalence in different months varied ranging from 83.3% to 91.7%, with the highest prevalence in summer. Nestling groups showed obviously high infection than adult pigeons. [Conclusion] The present survey indicated the wide and severe prevalence of Eimeria infection in Guangdong domestic pigeons, which suggested that integrated measures should be taken to control and prevent coccidiosis of pigeons in this province.展开更多
基金supported by National Key Research and Development Program of China(2023YFD1200500,2022YFD1201700)the National Natural Science Foundation of China(32071921)+1 种基金Key Research and Development Program of Shandong Province,China(2021LZGC022)the Taishan Scholars Project。
文摘Maize(Zea mays L.)is one of the world's most important staple crops,and is used for manufacturing food,feed,and industrial products.A key factor in maize yield is the grain weight,which directly influences productivity.In this study,we revealed the role of smk23 in maize kernel development.The ethyl methanesulfonate mutant smk23 is characterized by substantially reduced kernel weight.Through map-based cloning,smk23 was found to be located on Chr5 and encode a putative B-type response regulator,Zm RR5.A change from G to A occurs in the coding sequence of Zm RR5,resulting in the early termination of smk23.In Arabidopsis,B-type response regulators are involved in cytokinin signaling.Histological analysis and in situ hybridization of the mutant revealed abnormal endosperm development,particularly in the basal endosperm transfer layer(BETL),a specialized tissue critical for nutrient transport from the maternal tissues to the developing kernel.Zm RR5 positively regulates key genes involved in BETL development and function,including MRP1 and TCRR1.Furthermore,RNA sequencing revealed that several genes closely linked to BETL development,including BETL2,MEG1,and MN1,were significantly downregulated in smk23.These genes are essential for nutrient transport,tissue development and signal transduction.In addition,haploid analysis of Zm RR5 revealed natural variations(Hap 2)that may contribute to the increased kernel yield.Disruption of Zm RR5 function in smk23 leads to defects in BETL development,impairing its ability to transport nutrients,and ultimately resulting in a smaller kernel size.This study provides new insights into the molecular mechanisms through which Zm RR5 regulates maize kernel development and offers potential strategies for improving grain yield.
基金Support by the National Natural Science Foundation of China(Grant No.31402186 and 31302086)the Pearl River Science and Technology New Star Project(Grant No.2012J2200059 and 2014J2200096)+1 种基金the Dean Foundation of Guangdong Academy of Agricultural Sciences(Grant No.201413)the Science and Technology Plan Projects of Guangdong Province(Grant No.2015A020209075,2013B031500005,2014B070706011 and 2013B060400037)
文摘[Objective] This study aimed to make a survey of domestic pigeons for infection with Eimeria species of coccidia was conducted in Guangdong Province, southern China. [Method] A total of 244 fecal samples(102 from Huizhou, 83 from Jiangmen, 35 from Chaozhou and 24 from Guangzhou, respectively) in four pigeon breeding farms between June 2012 and March2013 were collected and examined microscopically. [Results] Eimeria oocysts were seen in 223(91.4%) fecal samples, with three species, namely E. labbeana, E.columbae and E. kapotei. E. labbeana was the most common species in Guangdong provinces with an overall prevalence of 91.4%, while a slightly lower incidence of E. columbae and E. kapotei species was detected with11.1% and 6.6%, representatively. The prevalence in different months varied ranging from 83.3% to 91.7%, with the highest prevalence in summer. Nestling groups showed obviously high infection than adult pigeons. [Conclusion] The present survey indicated the wide and severe prevalence of Eimeria infection in Guangdong domestic pigeons, which suggested that integrated measures should be taken to control and prevent coccidiosis of pigeons in this province.
