Plant growth-promoting rhizobacteria(PGPR) located in rhizobacteria soil are beneficial to plant growth and development. A PGPR strain AMCC100017 of Brevibacillus laterosporus synthesizes the plant hormone IAA in a tr...Plant growth-promoting rhizobacteria(PGPR) located in rhizobacteria soil are beneficial to plant growth and development. A PGPR strain AMCC100017 of Brevibacillus laterosporus synthesizes the plant hormone IAA in a tryptophan-dependent manner. In this study, the AMCC100017 strain was used to treat Malus robusta, an excellent natural rootstock for apple production, and assess its ability to promote growth. The fresh weight, dry weight, plant height, and lateral root growth of M. robusta were significantly increased with treatment. The presence of the AMCC100017 strain increased IAA content in M. robusta and promoted root secretion of tryptophan. Colonization of the strain in the roots allowed continuous synthesis of IAA and promoted plant growth. In addition, the photosynthetic efficiency in leaves increased after microbial treatment, and the utilization of nitrogen, zinc, iron, copper and magnesium in leaves was increased, which was conducive to photosynthesis.Interestingly, the activities of CAT and SOD, as well as the contents of ROS in plants colonized by AMCC100017 were increased compared to control plants, but the activities of POD and MDA contents were decreased. AMCC100017 strain affected the antioxidant capacity and stress resistance of plants. AMCC100017 strain increased the content of soluble protein and soluble sugar in plants, improved plant metabolic activity and stress resistance. Therefore, AMCC100017 not only increased IAA content and photosynthetic efficiency to promote M. robusta growth, but also affected plant through multiple metabolic pathways.展开更多
Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR associated 9(CRISPR/Cas9)system has recently become one popular technology due to its efficiency,precision,and simplicity compared with other genome edi...Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR associated 9(CRISPR/Cas9)system has recently become one popular technology due to its efficiency,precision,and simplicity compared with other genome editing tools such as Zinc Finger Nucleases(ZFNs)and Transcription Activator Like Effector Nucleases(TALENs).Horticultural crops provide energy and health-keeping nutrients to humankind.Genome-editing technology has become widely adopted in horticultural breeding with the increasing demand for high yield and better-quality horticultural crops.Here,we describe the CRISPR/Cas9 system construction,its optimization,including sgRNA promoter,sgRNA design,Cas9 protein promoter,SpCas9 variants and orthologs,and vector delivery methods.We also summarized the application of this technology in horticultural plants for stress responses enhancement,fruit quality improvement,and cultivation traits modification.This detailed review was compiled to help establish comprehensive understanding of the CRISPR/Cas9 systems and provide a reference for further developing this technology to manipulate horticultural plant traits effectively.展开更多
The CLAVATA3/EMBRYO SURROUNDING REGION-related(CLE)peptides are critical for stem cell homeostasis in plant shoot and root apical meristem.Although CLE genes have been reported in numerous plants,there is limited info...The CLAVATA3/EMBRYO SURROUNDING REGION-related(CLE)peptides are critical for stem cell homeostasis in plant shoot and root apical meristem.Although CLE genes have been reported in numerous plants,there is limited information for apple.Here,twenty-five MdCLE genes were identified fromapple genome(Apple Genome V1.0 predicted peptides).Analysis of chromosomal location showed that the 25 MdCLE genes were located on 12 of 17 apple chromosomes.Genetic structure analysis showed that 21 of 25 the MdCLE genes were intron-free.Expression patterns showed thatmost of the MdCLE genes showed higher expression levels in leaves and root compared with the other tissues.In addition,expression analysis demonstrated that MdCLE genes had different gene expression patterns for abiotic stress treatment,suggesting their potential roles in acclimation of apple to adverse environments.The 25 MdCLE genes encoded 19 different CLE peptides,and they were divided into two groups depending on their effects on the inhibition of Arabidopsis root growth.Our results suggest that MdCLE genesmay have an important but redundant function in regulating plant growth and development,and this work provides valuable references for further investigation of the biological functions of MdCLE genes.展开更多
A homologous gene of strigolactones repressor protein gene SMXL7/D53,MdSMXL8.2(GenBank accession No.:MD07G1222400),was cloned from‘Royal Gala’apple(Malus×domestica Borkh.)in this study.The sequence analysis rev...A homologous gene of strigolactones repressor protein gene SMXL7/D53,MdSMXL8.2(GenBank accession No.:MD07G1222400),was cloned from‘Royal Gala’apple(Malus×domestica Borkh.)in this study.The sequence analysis revealed that the length of this gene was 3243 bp,which encoded 1080 amino acids,and had a protein molecular mass of∼110 kD.The phylogenetic tree analysis indicated that the MdSMXL8.2 exhibited the highest sequence similarity with Arabidopsis AtSMXL7.The protein conserved domain analysis revealed that the MdSMXL8.2 contained two ClpA domains.The prediction of the secondary and tertiary structures of the MdSMXL8.2 indicated that it contained 34.54%αhelix,3.43%β-sheet,and 11.76%extended chain.The in-silico analysis suggested that the promoter sequence of MdSMXL8.2 contained several typical cisacting elements,including abscisic acid(ABA),gibberellin(GA),ethylene,auxin,jasmonic acid(JA),salicylic acid(SA),drought,and heat stressresponsive elements.Quantitative real-time(qRT)-PCR analyses revealed that MdSMXL8.2 was expressed in different apple tissues,with the highest transcript level found in the stem.The expression of MdSMXL8.2 was significantly induced by exogenous ABA,PEG and mannitol,while exogenous NaCl significantly inhibited MdSMXL8.2 expression.The growing status of MdSMXL8.2-overexpressed Orin apple callus was worse than the wild type(WT)after NaCl treatment and had a higher malondialdehyde(MDA)content and relative conductance(REC).Additionally,MdSMXL8.2-overexpressed Arabidopsis exhibited shorter root length and a reduction in fresh weight under salt stress,indicating that MdSMXL8.2 negatively regulated salt tolerance in apples.展开更多
The auxin receptor(TIR1/AFBs)family encodes the F-box protein subunit,which is involved in the formation of the E3 ubiquitin ligase SCFTIR1/AFBs complex,a key component of the auxin signaling pathway.However,there are...The auxin receptor(TIR1/AFBs)family encodes the F-box protein subunit,which is involved in the formation of the E3 ubiquitin ligase SCFTIR1/AFBs complex,a key component of the auxin signaling pathway.However,there are few studies on the auxin receptor family in apple(Malus×domestica).In this study,eight MdAFBs were identified,and phylogenetic analysis showed that they were classified into four groups and distributed on eight chromosomes.Herein,a comprehensive analysis of the MdAFB gene family was conducted to identify cis-acting elements,gene structures,protein structures,aligned sequences,conserved motifs,conserved amino acids,and the protein–protein interaction network.The results of yeast two-hybrid assays showed that MdAFB1 interacted with three auxin repressor proteins.The results of qRT-PCR showed that MdAFB1 responded to osmotic and salt stress.The overexpression of MdAFB1 increased osmotic and salt resistance in apple calli,and the ectopic expression of MdAFB1 enhanced osmotic and salt tolerance in Arabidopsis.This study provided a basis for the identification of auxin receptor genes in apple and their functions in mediating osmotic and salt stress.展开更多
Ascorbic acid(AsA,vitamin C)is involved in the regulation of many aspects of plant growth and development.It is an essential micronutrient for humans and can prevent scurvy,maintain the health of gums and blood vessel...Ascorbic acid(AsA,vitamin C)is involved in the regulation of many aspects of plant growth and development.It is an essential micronutrient for humans and can prevent scurvy,maintain the health of gums and blood vessels,reduce the level of plasma cholesterol and enhance the immune systen.Apple cultivars Orin and Guanghui were crossed to obtain a group of hybrid offspring with and without red flesh in the course of assessing apple germplasm resources.Unexpectedly,the red-flesh apples had higher AsA contents than other apples.Further studies showed that the anthocyanin biosynthetic regulator MdMYBl directly activates the expression of dehydroascorbate reductase gene MdDHAR,thus promoting the activity of the DHAR enzyme and the accumulation of AsA.This finding reveals the mechanism leading to high AsA levels in red-flesh apples and suggests a new idea to cultivate red-flesh apples with high AsA contents and produce AsA efficiently and without pollution.展开更多
基金financially supported by grants from the National Key Research and Development Program of China (Grant No. 2018YFD1000100)Science and Technology Program of Yunnan Province (Grant No. 2019ZG002-1-03)+2 种基金Ministry of Agriculture of China (Grant No. CARS-27)Major Applied Agricultural Technology Innovation Projects of Shandong Province (Grant No.SD2019ZZ009)Melon and Vegetable Industry Technology Collaborative Innovation Center of Ningxia Hui Autonomous Region(Grant No. 2017DC55)。
文摘Plant growth-promoting rhizobacteria(PGPR) located in rhizobacteria soil are beneficial to plant growth and development. A PGPR strain AMCC100017 of Brevibacillus laterosporus synthesizes the plant hormone IAA in a tryptophan-dependent manner. In this study, the AMCC100017 strain was used to treat Malus robusta, an excellent natural rootstock for apple production, and assess its ability to promote growth. The fresh weight, dry weight, plant height, and lateral root growth of M. robusta were significantly increased with treatment. The presence of the AMCC100017 strain increased IAA content in M. robusta and promoted root secretion of tryptophan. Colonization of the strain in the roots allowed continuous synthesis of IAA and promoted plant growth. In addition, the photosynthetic efficiency in leaves increased after microbial treatment, and the utilization of nitrogen, zinc, iron, copper and magnesium in leaves was increased, which was conducive to photosynthesis.Interestingly, the activities of CAT and SOD, as well as the contents of ROS in plants colonized by AMCC100017 were increased compared to control plants, but the activities of POD and MDA contents were decreased. AMCC100017 strain affected the antioxidant capacity and stress resistance of plants. AMCC100017 strain increased the content of soluble protein and soluble sugar in plants, improved plant metabolic activity and stress resistance. Therefore, AMCC100017 not only increased IAA content and photosynthetic efficiency to promote M. robusta growth, but also affected plant through multiple metabolic pathways.
基金supported by grants from the National Key R&D Program of China (Grant No. 2018YFD1000100)National Natural Science Foundation of China (Grant No. 31972378)Agricultural Variety Improvement Project of Shandong Province (Grant No. 2019LZGC007)
文摘Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR associated 9(CRISPR/Cas9)system has recently become one popular technology due to its efficiency,precision,and simplicity compared with other genome editing tools such as Zinc Finger Nucleases(ZFNs)and Transcription Activator Like Effector Nucleases(TALENs).Horticultural crops provide energy and health-keeping nutrients to humankind.Genome-editing technology has become widely adopted in horticultural breeding with the increasing demand for high yield and better-quality horticultural crops.Here,we describe the CRISPR/Cas9 system construction,its optimization,including sgRNA promoter,sgRNA design,Cas9 protein promoter,SpCas9 variants and orthologs,and vector delivery methods.We also summarized the application of this technology in horticultural plants for stress responses enhancement,fruit quality improvement,and cultivation traits modification.This detailed review was compiled to help establish comprehensive understanding of the CRISPR/Cas9 systems and provide a reference for further developing this technology to manipulate horticultural plant traits effectively.
基金This research was funded by National Key R&D Program of China(Grant No.2018YFD1000100)National Natural Science Foundation of China(Grant No.31772288)+1 种基金Ministry of Agriculture of China(Grant No.CARS-27)Science and Technology Program of Yunnan Province(Grant No.2019ZG002-1-03).
文摘The CLAVATA3/EMBRYO SURROUNDING REGION-related(CLE)peptides are critical for stem cell homeostasis in plant shoot and root apical meristem.Although CLE genes have been reported in numerous plants,there is limited information for apple.Here,twenty-five MdCLE genes were identified fromapple genome(Apple Genome V1.0 predicted peptides).Analysis of chromosomal location showed that the 25 MdCLE genes were located on 12 of 17 apple chromosomes.Genetic structure analysis showed that 21 of 25 the MdCLE genes were intron-free.Expression patterns showed thatmost of the MdCLE genes showed higher expression levels in leaves and root compared with the other tissues.In addition,expression analysis demonstrated that MdCLE genes had different gene expression patterns for abiotic stress treatment,suggesting their potential roles in acclimation of apple to adverse environments.The 25 MdCLE genes encoded 19 different CLE peptides,and they were divided into two groups depending on their effects on the inhibition of Arabidopsis root growth.Our results suggest that MdCLE genesmay have an important but redundant function in regulating plant growth and development,and this work provides valuable references for further investigation of the biological functions of MdCLE genes.
基金This study was financially supported by the Shandong Province(Grant No.2019LZGC007,SDAIT-06-03)National Natural Science Foundation of China(Grant No.31430074,U1706202)National Modern Apple Industry Technology System of China(Grant No.CARS-27).
文摘A homologous gene of strigolactones repressor protein gene SMXL7/D53,MdSMXL8.2(GenBank accession No.:MD07G1222400),was cloned from‘Royal Gala’apple(Malus×domestica Borkh.)in this study.The sequence analysis revealed that the length of this gene was 3243 bp,which encoded 1080 amino acids,and had a protein molecular mass of∼110 kD.The phylogenetic tree analysis indicated that the MdSMXL8.2 exhibited the highest sequence similarity with Arabidopsis AtSMXL7.The protein conserved domain analysis revealed that the MdSMXL8.2 contained two ClpA domains.The prediction of the secondary and tertiary structures of the MdSMXL8.2 indicated that it contained 34.54%αhelix,3.43%β-sheet,and 11.76%extended chain.The in-silico analysis suggested that the promoter sequence of MdSMXL8.2 contained several typical cisacting elements,including abscisic acid(ABA),gibberellin(GA),ethylene,auxin,jasmonic acid(JA),salicylic acid(SA),drought,and heat stressresponsive elements.Quantitative real-time(qRT)-PCR analyses revealed that MdSMXL8.2 was expressed in different apple tissues,with the highest transcript level found in the stem.The expression of MdSMXL8.2 was significantly induced by exogenous ABA,PEG and mannitol,while exogenous NaCl significantly inhibited MdSMXL8.2 expression.The growing status of MdSMXL8.2-overexpressed Orin apple callus was worse than the wild type(WT)after NaCl treatment and had a higher malondialdehyde(MDA)content and relative conductance(REC).Additionally,MdSMXL8.2-overexpressed Arabidopsis exhibited shorter root length and a reduction in fresh weight under salt stress,indicating that MdSMXL8.2 negatively regulated salt tolerance in apples.
基金supported by the National Natural Science Foundation of China(Grant Nos.32172538,31972378)China Agriculture Research System of MOF and MARA(Grant CARS-27).
文摘The auxin receptor(TIR1/AFBs)family encodes the F-box protein subunit,which is involved in the formation of the E3 ubiquitin ligase SCFTIR1/AFBs complex,a key component of the auxin signaling pathway.However,there are few studies on the auxin receptor family in apple(Malus×domestica).In this study,eight MdAFBs were identified,and phylogenetic analysis showed that they were classified into four groups and distributed on eight chromosomes.Herein,a comprehensive analysis of the MdAFB gene family was conducted to identify cis-acting elements,gene structures,protein structures,aligned sequences,conserved motifs,conserved amino acids,and the protein–protein interaction network.The results of yeast two-hybrid assays showed that MdAFB1 interacted with three auxin repressor proteins.The results of qRT-PCR showed that MdAFB1 responded to osmotic and salt stress.The overexpression of MdAFB1 increased osmotic and salt resistance in apple calli,and the ectopic expression of MdAFB1 enhanced osmotic and salt tolerance in Arabidopsis.This study provided a basis for the identification of auxin receptor genes in apple and their functions in mediating osmotic and salt stress.
基金grants from the Agricultural Variety Improvement Project of Shandong Province(2019LZGC007)Fruit quality improvement of Yunnan Province(2019ZG002)the Natural Science Foundation of Shandong Province(ZR2019PC004).
文摘Ascorbic acid(AsA,vitamin C)is involved in the regulation of many aspects of plant growth and development.It is an essential micronutrient for humans and can prevent scurvy,maintain the health of gums and blood vessels,reduce the level of plasma cholesterol and enhance the immune systen.Apple cultivars Orin and Guanghui were crossed to obtain a group of hybrid offspring with and without red flesh in the course of assessing apple germplasm resources.Unexpectedly,the red-flesh apples had higher AsA contents than other apples.Further studies showed that the anthocyanin biosynthetic regulator MdMYBl directly activates the expression of dehydroascorbate reductase gene MdDHAR,thus promoting the activity of the DHAR enzyme and the accumulation of AsA.This finding reveals the mechanism leading to high AsA levels in red-flesh apples and suggests a new idea to cultivate red-flesh apples with high AsA contents and produce AsA efficiently and without pollution.
