Adverse environmental factors severely affect crop productivity.Improving crop resistance to multiple stressors is an important breeding goal.Although CBFs/DREB1s extensively participate in plant resistance to abiotic...Adverse environmental factors severely affect crop productivity.Improving crop resistance to multiple stressors is an important breeding goal.Although CBFs/DREB1s extensively participate in plant resistance to abiotic stress,the common mechanism underlying CBFs/DREB1s that mediate resistance to multiple stressors remains unclear.Here,we show the common mechanism for MaDREB1F conferring cold and drought stress resistance in banana.MaDREB1F encodes a dehydration-responsive element binding protein(DREB)transcription factor with nuclear localization and transcriptional activity.MaDREB1F expression is significantly induced after cold,osmotic,and salt treatments.MaDREB1F overexpression increases banana resistance to cold and drought stress by common modulation of the protectant metabolite levels of soluble sugar and proline,activating the antioxidant system,and promoting jasmonate and ethylene syntheses.Transcriptomic analysis shows that MaDREB1F activates or alleviates the repression of jasmonate and ethylene biosynthetic genes under cold and drought conditions.Moreover,MaDREB1F directly activates the promoter activities of MaAOC4 and MaACO_(2)0 for jasmonate and ethylene syntheses,respectively,under cold and drought conditions.MaDREB1F also targets the MaERF11 promoter to activate MaACO_(2)0 expression for ethylene synthesis under drought stress.Together,our findings offer new insight into the common mechanism underlying CBF/DREB1-mediated cold and drought stress resistance,which has substantial implications for engineering cold-and drought-tolerant crops.展开更多
Starch branching enzyme(SBE)has rarely been studied in common starchy banana fruits.For the first time,we report here the molecular characterization of seven SBE(MaSBE)and six SBE(MbSBE)genes in the banana A-and B-gen...Starch branching enzyme(SBE)has rarely been studied in common starchy banana fruits.For the first time,we report here the molecular characterization of seven SBE(MaSBE)and six SBE(MbSBE)genes in the banana A-and B-genomes,respectively,which could be classified into three distinct subfamilies according to genome-wide identification.Systematic transcriptomic analysis revealed that six MaSBEs and six MbSBEs were expressed in the developing banana fruits of two different genotypes,BaXi Jiao(BX,AAA)and Fen Jiao(FJ,AAB),among which MaSBE2.3 and MbSBE2.3 were highly expressed.Transient silencing of MaSBE2.3 expression in banana fruit discs led to a significant decrease in its transcription,which coincides with significant reductions in total starch and amylopectin contents compared to those of empty vector controls.The suggested functional role of MaSBE2.3 in banana fruit development was corroborated by its transient overexpression in banana fruit discs,which led to significant enhancements in total starch and amylopectin contents.A number of transcription factors,including three auxin response factors(ARF2/12/24)and two MYBs(MYB3/308),that interact with the MaSBE2.3 promoter were identified by yeast one-hybrid library assays.Among these ARFs and MYBs,MaARF2/MaMYB308 and MaARF12/MaARF24/MaMYB3 were demonstrated via a luciferase reporter system to upregulate and downregulate the expression of MaSBE2.3,respectively.展开更多
As one of the most important economic crops for both staple food and fruit widely cultivated in the tropics and subtropics,banana(Musa spp.)is susceptible to a plethora of abiotic and biotic stresses.Breeding cultivar...As one of the most important economic crops for both staple food and fruit widely cultivated in the tropics and subtropics,banana(Musa spp.)is susceptible to a plethora of abiotic and biotic stresses.Breeding cultivars resistant to abiotic and biotic stressors without adverse effects on yield and fruit quality are the objectives of banana improvement programs.However,conventional breeding approaches are time-consuming and severely hampered by inherent banana problems(polyploidy and sterility).Therefore,genetic transformation is becoming increasingly popular and can provide rapid solutions.Numerous efforts have been made to develop superior banana cultivars with better resistance to abiotic and biotic stresses and optimum yields using genetic modification strategies.Somatic embryogenesis(SE)through embryogenic cell suspension(ECS)cultures is an ideal recipient system for genetic transformation in banana.The purpose of this paper is to review the current status of banana somatic embryo research,clarify the process of banana somatic embryo induction and culture,and summarize the main influencing factors in the process of somatic embryogenesis.At the same time,their applications in breeding technologies such as cryopreservation,protoplast culture,genetic transformation and gene editing were also summarized,in order to provide reference for the research and practical application of banana somatic embryogenesis in the future.展开更多
An array of two substrate-integrated waveguide(SIW) periodic leaky-wave antennas(LWAs) with sum and difference beam scanning is proposed for application in target detection and tracking. The array is composed of two p...An array of two substrate-integrated waveguide(SIW) periodic leaky-wave antennas(LWAs) with sum and difference beam scanning is proposed for application in target detection and tracking. The array is composed of two periodic LWAs with different periods, in which each LWA generates a narrow beam through the n=-1 space harmonic. Due to the two different periods for the two LWAs, two beams with two different directions can be realized, which can be combined into a sum beam when the array is fed in phase or into a difference beam when the array is fed 180?out of phase. The array integrated with 180?hybrid is designed, fabricated, and measured.Measurement results show that the sum beam can reach a gain up to 15.9 dBi and scan from-33.4?to 20.8?. In the scanning range, the direction of the null in the difference beam is consistent with the direction of the sum beam,with the lowest null depth of-40.8 dB. With the excellent performance, the antenna provides an alternative solution with low complexity and low cost for target detection and tracking.展开更多
β-amylase(BAM) is an important enzyme involved in conversion of starch to maltose in multiple biological processes in plants. However, there is currently insufficient information on the BAM gene family in the importa...β-amylase(BAM) is an important enzyme involved in conversion of starch to maltose in multiple biological processes in plants. However, there is currently insufficient information on the BAM gene family in the important fruit crop banana. This study identified 16 BAM genes in the banana genome. Phylogenetic analysis showed that Ma BAMs were classified into four subfamilies. Most Ma BAMs in each subfamily shared similar gene structures. Conserved motif analysis showed that all identified Ma BAM proteins had the typical glyco hydro14 domains. Comprehensive transcriptomic analysis of two banana genotypes revealed the expression patterns of Ma BAMs in different tissues, at various stages of fruit development and ripening, and in responses to abiotic stresses. Most Ma BAMs showed strong transcript accumulation changes during fruit development and late-stage ripening. Some Ma BAMs showed significant changes under cold, salt, and osmotic stresses. This finding indicated that Ma BAMs might be involved in regulating fruit development, ripening, and responses to abiotic stress. Analysis of five hormone-related and seven stressrelevant elements in the promoters of Ma BAMs further revealed that BAMs participated in various biological processes. This systemic analysis provides new insights into the transcriptional characteristics of the BAM genes in banana and may serve as a basis for further functional studies of such genes.展开更多
Cold stress is an environmental factor affecting plant development and production. Recently,micro RNAs(mi RNAs) have been found to be involved in several plant processes such as growth regulation and stress responses....Cold stress is an environmental factor affecting plant development and production. Recently,micro RNAs(mi RNAs) have been found to be involved in several plant processes such as growth regulation and stress responses. Although mi RNAs and their targets have been identified in several banana species, their participation during cold accumulation in banana remains unknown. In this study, two small RNA libraries were generated from micropropagated plantlets of Musa balbisiana grown at normal and low temperature(5°C).A total of 69 known mi RNAs and 32 putative novel mi RNAs were detected in the libraries by Solexa sequencing. Sixty-four cold-inducible mi RNAs were identified through differentially expressed mi RNAs analysis. Among 43 mi RNAs belonging to 26 conserved mi RNA families with altered expression, 18 were upregulated and 25 downregulated under cold stress. Of21 putative novel mi RNAs with altered expression, four were downregulated and 17 upregulated. Furthermore,eight mi RNAs were validated by stem-loop q RT-PCR and their dynamic differential expression was analyzed. In addition, 393 target genes of 58 identified cold-responsive mi RNAs were predicted and categorized by function.These results provide important information for further characterization and functional analysis of cold-responsive mi RNAs in banana.展开更多
Banana(Musa spp.) is an important staple food, economic crop, and nutritional fruit worldwide.Hybridization is seriously hampered by the long generation time, polyploidy, and sterility of most cultivars.Establishment ...Banana(Musa spp.) is an important staple food, economic crop, and nutritional fruit worldwide.Hybridization is seriously hampered by the long generation time, polyploidy, and sterility of most cultivars.Establishment of an efficient regeneration and transformation system for banana is critical for their genetic improvement. An efficient and reproducible transformation system for banana using direct organogenesis was developed. Media containing benzylaminopurine(BA)combined with one of four other growth regulators was evaluated for the regeneration efficiency of five Musa cultivars and the ability to induce/support development of new banana shoots. The result indicated that the greatest number of shoots per explant for all five Musa cultivars was obtained using MS medium supplemented with8.9 mmol$L–1BA and 9.1 mmol$L–1thidiazuron(TDZ).In 240–270 d, one immature male flower could regenerate between 380 and 456, 310–372, 200–240, 130–156, and100–130 well-developed shoots for Gongjiao, Red banana, Rose banana, Baxi, and Xinglongnaijiao, respectively. Such a system will facilitate molecular breeding and functional genomics of banana.展开更多
基金the National Key Research and Development Program of China(2019YFD1000204)the 2020 Research Program of Sanya Yazhou Bay Science and Technology City(SKJC-2020-02-002)+1 种基金the National Natural Science Foundation of China(32260736)the Central Public-interest Scientific Institution Basal Research Fund for Chinese Academy of Tropical Agricultural Sciences(1630052020006)for funding resources.
文摘Adverse environmental factors severely affect crop productivity.Improving crop resistance to multiple stressors is an important breeding goal.Although CBFs/DREB1s extensively participate in plant resistance to abiotic stress,the common mechanism underlying CBFs/DREB1s that mediate resistance to multiple stressors remains unclear.Here,we show the common mechanism for MaDREB1F conferring cold and drought stress resistance in banana.MaDREB1F encodes a dehydration-responsive element binding protein(DREB)transcription factor with nuclear localization and transcriptional activity.MaDREB1F expression is significantly induced after cold,osmotic,and salt treatments.MaDREB1F overexpression increases banana resistance to cold and drought stress by common modulation of the protectant metabolite levels of soluble sugar and proline,activating the antioxidant system,and promoting jasmonate and ethylene syntheses.Transcriptomic analysis shows that MaDREB1F activates or alleviates the repression of jasmonate and ethylene biosynthetic genes under cold and drought conditions.Moreover,MaDREB1F directly activates the promoter activities of MaAOC4 and MaACO_(2)0 for jasmonate and ethylene syntheses,respectively,under cold and drought conditions.MaDREB1F also targets the MaERF11 promoter to activate MaACO_(2)0 expression for ethylene synthesis under drought stress.Together,our findings offer new insight into the common mechanism underlying CBF/DREB1-mediated cold and drought stress resistance,which has substantial implications for engineering cold-and drought-tolerant crops.
基金sponsored by the National Key R&D Program of China(No.2018YFD1000200 and 2019YFD1000200)the Modern Agro-industry Technology Research System of China(No.CARS-31)+1 种基金the Central Publicinterest Scientific Institution Basal Research Fund(Nos.1630052020002,1630052017010,and 1630052016006)the National Natural Science Foundation of China(NSFC,No.31401843).
文摘Starch branching enzyme(SBE)has rarely been studied in common starchy banana fruits.For the first time,we report here the molecular characterization of seven SBE(MaSBE)and six SBE(MbSBE)genes in the banana A-and B-genomes,respectively,which could be classified into three distinct subfamilies according to genome-wide identification.Systematic transcriptomic analysis revealed that six MaSBEs and six MbSBEs were expressed in the developing banana fruits of two different genotypes,BaXi Jiao(BX,AAA)and Fen Jiao(FJ,AAB),among which MaSBE2.3 and MbSBE2.3 were highly expressed.Transient silencing of MaSBE2.3 expression in banana fruit discs led to a significant decrease in its transcription,which coincides with significant reductions in total starch and amylopectin contents compared to those of empty vector controls.The suggested functional role of MaSBE2.3 in banana fruit development was corroborated by its transient overexpression in banana fruit discs,which led to significant enhancements in total starch and amylopectin contents.A number of transcription factors,including three auxin response factors(ARF2/12/24)and two MYBs(MYB3/308),that interact with the MaSBE2.3 promoter were identified by yeast one-hybrid library assays.Among these ARFs and MYBs,MaARF2/MaMYB308 and MaARF12/MaARF24/MaMYB3 were demonstrated via a luciferase reporter system to upregulate and downregulate the expression of MaSBE2.3,respectively.
基金supported by the specific research fund of The Innovation Platform for Academicians of Hainan Province(YSPTZX202101)the Hainan Provincial Natural Science Foundation(321RC638),the National Natural Science Foundation of China(32172269,31501043)the Earmarked Fund for Modern Agro-industry Technology Research System(CARS-31).
文摘As one of the most important economic crops for both staple food and fruit widely cultivated in the tropics and subtropics,banana(Musa spp.)is susceptible to a plethora of abiotic and biotic stresses.Breeding cultivars resistant to abiotic and biotic stressors without adverse effects on yield and fruit quality are the objectives of banana improvement programs.However,conventional breeding approaches are time-consuming and severely hampered by inherent banana problems(polyploidy and sterility).Therefore,genetic transformation is becoming increasingly popular and can provide rapid solutions.Numerous efforts have been made to develop superior banana cultivars with better resistance to abiotic and biotic stresses and optimum yields using genetic modification strategies.Somatic embryogenesis(SE)through embryogenic cell suspension(ECS)cultures is an ideal recipient system for genetic transformation in banana.The purpose of this paper is to review the current status of banana somatic embryo research,clarify the process of banana somatic embryo induction and culture,and summarize the main influencing factors in the process of somatic embryogenesis.At the same time,their applications in breeding technologies such as cryopreservation,protoplast culture,genetic transformation and gene editing were also summarized,in order to provide reference for the research and practical application of banana somatic embryogenesis in the future.
基金Project supported in part by the National Natural Science Foundation of China(No.62171480)in part by the Guangdong Basic and Applied Basic Research Foundation,China(No.2020B1515020053)。
文摘An array of two substrate-integrated waveguide(SIW) periodic leaky-wave antennas(LWAs) with sum and difference beam scanning is proposed for application in target detection and tracking. The array is composed of two periodic LWAs with different periods, in which each LWA generates a narrow beam through the n=-1 space harmonic. Due to the two different periods for the two LWAs, two beams with two different directions can be realized, which can be combined into a sum beam when the array is fed in phase or into a difference beam when the array is fed 180?out of phase. The array integrated with 180?hybrid is designed, fabricated, and measured.Measurement results show that the sum beam can reach a gain up to 15.9 dBi and scan from-33.4?to 20.8?. In the scanning range, the direction of the null in the difference beam is consistent with the direction of the sum beam,with the lowest null depth of-40.8 dB. With the excellent performance, the antenna provides an alternative solution with low complexity and low cost for target detection and tracking.
基金supported by the National Natural Science Foundation of China (31401843)the Modern Agro-industry Technology Research System (CARS-32)+2 种基金the National Nonprofit Institute Research Grant of CATAS-ITBB (1630052016006)the National Program on Key Basic Research Project of China (2014CB160314)the Natural Science Foundation of Hainan Province (314100)
文摘β-amylase(BAM) is an important enzyme involved in conversion of starch to maltose in multiple biological processes in plants. However, there is currently insufficient information on the BAM gene family in the important fruit crop banana. This study identified 16 BAM genes in the banana genome. Phylogenetic analysis showed that Ma BAMs were classified into four subfamilies. Most Ma BAMs in each subfamily shared similar gene structures. Conserved motif analysis showed that all identified Ma BAM proteins had the typical glyco hydro14 domains. Comprehensive transcriptomic analysis of two banana genotypes revealed the expression patterns of Ma BAMs in different tissues, at various stages of fruit development and ripening, and in responses to abiotic stresses. Most Ma BAMs showed strong transcript accumulation changes during fruit development and late-stage ripening. Some Ma BAMs showed significant changes under cold, salt, and osmotic stresses. This finding indicated that Ma BAMs might be involved in regulating fruit development, ripening, and responses to abiotic stress. Analysis of five hormone-related and seven stressrelevant elements in the promoters of Ma BAMs further revealed that BAMs participated in various biological processes. This systemic analysis provides new insights into the transcriptional characteristics of the BAM genes in banana and may serve as a basis for further functional studies of such genes.
基金supported by the grants from the National Natural Science Foundation of China (31501043)the Ministry of Science and Technology of the People’s Republic of China (2011AA10020605)the Earmarked Fund for Modern Agro-industry Technology Research System (CARS-32)
文摘Cold stress is an environmental factor affecting plant development and production. Recently,micro RNAs(mi RNAs) have been found to be involved in several plant processes such as growth regulation and stress responses. Although mi RNAs and their targets have been identified in several banana species, their participation during cold accumulation in banana remains unknown. In this study, two small RNA libraries were generated from micropropagated plantlets of Musa balbisiana grown at normal and low temperature(5°C).A total of 69 known mi RNAs and 32 putative novel mi RNAs were detected in the libraries by Solexa sequencing. Sixty-four cold-inducible mi RNAs were identified through differentially expressed mi RNAs analysis. Among 43 mi RNAs belonging to 26 conserved mi RNA families with altered expression, 18 were upregulated and 25 downregulated under cold stress. Of21 putative novel mi RNAs with altered expression, four were downregulated and 17 upregulated. Furthermore,eight mi RNAs were validated by stem-loop q RT-PCR and their dynamic differential expression was analyzed. In addition, 393 target genes of 58 identified cold-responsive mi RNAs were predicted and categorized by function.These results provide important information for further characterization and functional analysis of cold-responsive mi RNAs in banana.
基金supported by the earmarked fund for Modern Agro-Industry Technology Research System (CARS-32)the National Nonprofit Institute Research Grant of the Institute of Tropical Bioscience and Biotechnology CATAS-ITBB (ITBB2015ZY06)
文摘Banana(Musa spp.) is an important staple food, economic crop, and nutritional fruit worldwide.Hybridization is seriously hampered by the long generation time, polyploidy, and sterility of most cultivars.Establishment of an efficient regeneration and transformation system for banana is critical for their genetic improvement. An efficient and reproducible transformation system for banana using direct organogenesis was developed. Media containing benzylaminopurine(BA)combined with one of four other growth regulators was evaluated for the regeneration efficiency of five Musa cultivars and the ability to induce/support development of new banana shoots. The result indicated that the greatest number of shoots per explant for all five Musa cultivars was obtained using MS medium supplemented with8.9 mmol$L–1BA and 9.1 mmol$L–1thidiazuron(TDZ).In 240–270 d, one immature male flower could regenerate between 380 and 456, 310–372, 200–240, 130–156, and100–130 well-developed shoots for Gongjiao, Red banana, Rose banana, Baxi, and Xinglongnaijiao, respectively. Such a system will facilitate molecular breeding and functional genomics of banana.