Bean(Phaseolus vulgaris)is a globally important legume crop valued for its nutritional content and adaptability.Establishing a robust root system during early growth is critical for optimal nutrient uptake,shoot devel...Bean(Phaseolus vulgaris)is a globally important legume crop valued for its nutritional content and adaptability.Establishing a robust root system during early growth is critical for optimal nutrient uptake,shoot development,and increased resistance to biotic stress.This study evaluated the effects of exogenous indole-3-butyric acid(IBA)on root and shoot development in two bean cultivars,Onceler-98 and Topcu,during the seedling stage.IBA was applied at four concentrations:0(control),50,100,and 150μM.Morphological parameters measured included root length(RL),root fresh weight(RFW),root dry weight(RDW),root nodule number(RNN),shoot length(SL),shoot fresh weight(SFW),and shoot dry weight(SDW).The experiment followed a randomized complete block design with four replications.Significant(p≤0.05)and highly significant(p≤0.01)differences were observed across treatments and cultivars.The results indicated that Onceler-98 generally responded more favorably to IBA application,with optimal growth performance observed at 100μM.In contrast,Topcu was less responsive to IBA overall,and high concentrations-particularly 150μM-tended to suppress nodule formation.展开更多
The aerial parts of higher plants are generated from the shoot apical meristem （SAM）. In this study, we isolated a small rice （Oryza sativa L.） mutant that showed premature termination of shoot development and was...The aerial parts of higher plants are generated from the shoot apical meristem （SAM）. In this study, we isolated a small rice （Oryza sativa L.） mutant that showed premature termination of shoot development and was named mini rice 1 （mini1）. The mutant was first isolated from a japonica cultivar Zhonghua11 （ZH11） subjected to ethyl methanesulfonate （EMS） treatment. With bulked segregant analysis （BSA） and mapbased cloning method, Mini1 gene was finally fine-mapped to an interval of 48.6 kb on chromosome 9. Sequence analyses revealed a single base substitution from G to A was found in the region, which resulted in an amino acid change from Gly to Asp. The candidate gene Os09go363900 was predicted to encode a putative adhesion of calyx edges protein ACE （putative HOTHEAD precursor） and genetic complementation experiment confirmed the identity of Minil. Os09go36：3900 contains glucose-methanol-choline （GMC） oxidoreductase and NAD（P）-binding Rossmann-like domain, and exhibits high similarity to Arabidopsis HOTHEAD （HTH）. Expression analysis indicated Minil was highly expressed in young shoots but lowly in roots and the expression level of most genes involved in auxin biosynthesis and signal transduction were reduced in mutant. We conclude that Mini1 plays an important role in maintaining SAM activity and promoting shoot development in rice.展开更多
Microscopic imaging of fluorescent reporters for key meristem regulators in live tissues is emerging as a powerful technique, enabling researchers to observe dynamic spatial and temporal distribution of hormonal and d...Microscopic imaging of fluorescent reporters for key meristem regulators in live tissues is emerging as a powerful technique, enabling researchers to observe dynamic spatial and temporal distribution of hormonal and developmental regulators in living cells. Aided by time-lapse microphotography, new types of imaging acquisition and analysis software, and computational modeling, we are gaining significant insights into shoot apical meristem （SAM） behavior and function. This review is focused on summarizing recent advances in the understanding of SAM organization, development, and behavior derived from live-imaging techniques. This includes the revelation of mechanical forces in microtubule-controlled anisotropic growth, the role of the CLV-WUS network in the specification of peripheral zone and central zone cells, the multiple feedback loops involving cytokinin in controlling WUS expression, auxin dynamics in determining the position of new primordia, and, finally, sequence of regulatory events leading to de novo assembly of shoots from callus in culture. Future studies toward formulating ＂digital SAM＂ that incorporates multi-dimensional data ranging from images of SAM morphogenesis to a genome-scale expression map of SAM will greatly enhance our ability to understand, predict, and manipulate SAM, containing the stem cells that give rise to all above ground parts of a plant.展开更多
The indeterminate growth pattern displayed by shoots is mediated by the proper maintenance of the shoot meristem. Meristem maintenance is dependent upon the balance of stem cell perpetuation in the central zone （CZ）...The indeterminate growth pattern displayed by shoots is mediated by the proper maintenance of the shoot meristem. Meristem maintenance is dependent upon the balance of stem cell perpetuation in the central zone （CZ） and organogenesis in the peripheral zone （PZ）. Although the mechanisms that coordinate CZ and PZ function is not understood, meristem cell fate is likely achieved by the spatial interplay between gene regulatory networks and hormone signaling pathways. During shoot maturation, the identity of the shoot meristem as well as the lateral organs are transformed during the vegetative and reproductive transitions. Studies in model plant systems indicate that three amino acid extension （TALE） homeodomain proteins integrate signaling events that transform the identity of the shoot meristem and establish reproductive patterns of growth. This review will highlight the function of TALE homeodomain transcription factors that regulate shoot meristem cell fate and also function with phase specific regulators to maintain shoot meristem identity.展开更多
文摘Bean(Phaseolus vulgaris)is a globally important legume crop valued for its nutritional content and adaptability.Establishing a robust root system during early growth is critical for optimal nutrient uptake,shoot development,and increased resistance to biotic stress.This study evaluated the effects of exogenous indole-3-butyric acid(IBA)on root and shoot development in two bean cultivars,Onceler-98 and Topcu,during the seedling stage.IBA was applied at four concentrations:0(control),50,100,and 150μM.Morphological parameters measured included root length(RL),root fresh weight(RFW),root dry weight(RDW),root nodule number(RNN),shoot length(SL),shoot fresh weight(SFW),and shoot dry weight(SDW).The experiment followed a randomized complete block design with four replications.Significant(p≤0.05)and highly significant(p≤0.01)differences were observed across treatments and cultivars.The results indicated that Onceler-98 generally responded more favorably to IBA application,with optimal growth performance observed at 100μM.In contrast,Topcu was less responsive to IBA overall,and high concentrations-particularly 150μM-tended to suppress nodule formation.
基金supported by grants from the National Natural Science Foundation of China (No. 31201194)
文摘The aerial parts of higher plants are generated from the shoot apical meristem （SAM）. In this study, we isolated a small rice （Oryza sativa L.） mutant that showed premature termination of shoot development and was named mini rice 1 （mini1）. The mutant was first isolated from a japonica cultivar Zhonghua11 （ZH11） subjected to ethyl methanesulfonate （EMS） treatment. With bulked segregant analysis （BSA） and mapbased cloning method, Mini1 gene was finally fine-mapped to an interval of 48.6 kb on chromosome 9. Sequence analyses revealed a single base substitution from G to A was found in the region, which resulted in an amino acid change from Gly to Asp. The candidate gene Os09go363900 was predicted to encode a putative adhesion of calyx edges protein ACE （putative HOTHEAD precursor） and genetic complementation experiment confirmed the identity of Minil. Os09go36：3900 contains glucose-methanol-choline （GMC） oxidoreductase and NAD（P）-binding Rossmann-like domain, and exhibits high similarity to Arabidopsis HOTHEAD （HTH）. Expression analysis indicated Minil was highly expressed in young shoots but lowly in roots and the expression level of most genes involved in auxin biosynthesis and signal transduction were reduced in mutant. We conclude that Mini1 plays an important role in maintaining SAM activity and promoting shoot development in rice.
基金supported by the US National Science Foundation (IOB0616096 and MCB0744752)supported by the University of Maryland Agricultural Experiment Station
文摘Microscopic imaging of fluorescent reporters for key meristem regulators in live tissues is emerging as a powerful technique, enabling researchers to observe dynamic spatial and temporal distribution of hormonal and developmental regulators in living cells. Aided by time-lapse microphotography, new types of imaging acquisition and analysis software, and computational modeling, we are gaining significant insights into shoot apical meristem （SAM） behavior and function. This review is focused on summarizing recent advances in the understanding of SAM organization, development, and behavior derived from live-imaging techniques. This includes the revelation of mechanical forces in microtubule-controlled anisotropic growth, the role of the CLV-WUS network in the specification of peripheral zone and central zone cells, the multiple feedback loops involving cytokinin in controlling WUS expression, auxin dynamics in determining the position of new primordia, and, finally, sequence of regulatory events leading to de novo assembly of shoots from callus in culture. Future studies toward formulating ＂digital SAM＂ that incorporates multi-dimensional data ranging from images of SAM morphogenesis to a genome-scale expression map of SAM will greatly enhance our ability to understand, predict, and manipulate SAM, containing the stem cells that give rise to all above ground parts of a plant.
文摘The indeterminate growth pattern displayed by shoots is mediated by the proper maintenance of the shoot meristem. Meristem maintenance is dependent upon the balance of stem cell perpetuation in the central zone （CZ） and organogenesis in the peripheral zone （PZ）. Although the mechanisms that coordinate CZ and PZ function is not understood, meristem cell fate is likely achieved by the spatial interplay between gene regulatory networks and hormone signaling pathways. During shoot maturation, the identity of the shoot meristem as well as the lateral organs are transformed during the vegetative and reproductive transitions. Studies in model plant systems indicate that three amino acid extension （TALE） homeodomain proteins integrate signaling events that transform the identity of the shoot meristem and establish reproductive patterns of growth. This review will highlight the function of TALE homeodomain transcription factors that regulate shoot meristem cell fate and also function with phase specific regulators to maintain shoot meristem identity.
