Mikania micrantha is a fast-growing global invasive weed species that causes severe damage to natural ecosystems and very large economic losses of forest and crop production.It has advantages in photosynthesis,includi...Mikania micrantha is a fast-growing global invasive weed species that causes severe damage to natural ecosystems and very large economic losses of forest and crop production.It has advantages in photosynthesis,including a similar net photosynthetic rate as C4 plants and a higher carbon fixation capacity.We used a combination of genomics and transcriptomics approaches to study the evolutionary mechanisms and circadian expression patterns of M.micrantha.In M.micrantha,16 positive selection genes focused on photoreaction and utilization of photoassimilates.In different tissues,98.1%of the genes associated with photoresponse had high expression in stems,and more than half of the genes of the C4 cycle had higher expression in stems than in leaves.In stomatal opening and closing,2 genes of carbonic anhydrase(CAs)had higher expression at 18:00 than at 8:00,and the slow anion channel 1(SLAC1)and high-leaf-temperature 1 kinase(HT1)genes were expressed at low levels at 18:00.In addition,genes associated with photosynthesis had higher expression levels at 7:00 and 17:00.We hypothesized that M.micrantha may undergo photosynthesis in the stem and flower organs and that some stomata of the leaves were opening at night by CO_(2)signals.In addition,its evolution may attenuate photoinhibition at high light intensities,and enhance more efficient of photosynthesis during low light intensity.And the tissue-specific photosynthetic types and different diurnal pattern of photosynthetic-related genes may contribute to its rapid colonization of new habitats of M.micrantha.展开更多
[Objectives]The paper was to understand the occurrence and damage regularity of the invasive plant Mikania micrantha in Huadu District of Guangzhou.[Methods]The damage status of M.micranthFa in different forest lands ...[Objectives]The paper was to understand the occurrence and damage regularity of the invasive plant Mikania micrantha in Huadu District of Guangzhou.[Methods]The damage status of M.micranthFa in different forest lands and its annual growth dynamics were investigated by field investigation.[Results]With the change of canopy density from low to high,the occurrence degree of M.micrantha changed from high to low.The occurrence degree of M.micrantha in different forest land types was:abandoned orchard>wasteland>roadside greenbelt>waterside>forest edge>normally managed orchard.[Conclusions]M.micrantha enters the rapid growth period from March to May in spring,with the growth rate gradually slowing down after June.The result provides a theoretical basis and practical guidance for the prevention and control of M.micrantha.展开更多
Bridelia micrantha, commonly known as coastal golden leaf, is a member of the family Phyllanthaceae. In preliminary studies nine fractions, named F1 - F9, were obtained by fractionating the crude methanol extract of t...Bridelia micrantha, commonly known as coastal golden leaf, is a member of the family Phyllanthaceae. In preliminary studies nine fractions, named F1 - F9, were obtained by fractionating the crude methanol extract of the stem bark of Bridelia micrantha using column chromatographic techniques. The fraction F6 was the most active when tested for antibacterial activity. Thus, toxicity of this fraction was investigated for further use. The present study evaluated the acute and sub-chronic toxicity of the crude methanolic bark extract of Bridelia micrantha and its fraction. The acute toxicity was carried out according to the experimental protocol of Organization for Economic Co-operation and Development (OECD). The plant extract or the fraction F<sub>6</sub> was administered orally to female mice at a single dose of 2000 mg/kg and the animals were observed for any behavioral changes or mortality for 14 days. In the sub-chronic toxicity study, the extract and fraction were administered orally at 200, 400 and 800 mg/kg bw/day for 28 days to healthy Wistar rats. The general behavior and body weight of the rats were recorded daily. At the end of the experimental period, hematological and biochemical analyses, changes in vital organ weight (liver, lung, heart, spleen and kidney), and histopathological examination of the liver and kidney were performed. No mortality or adverse effects were noted at the 2000 mg/kg dose during the oral acute toxicity test. In the sub-chronic study, the crude methanolic bark extract of Bridelia micrantha and the fraction F<sub>6</sub> induced no mortality or treatment-related adverse effects on body weight, general behavior, relative organ weights, hematological and biochemical parameters. Histopathological examination of the liver and kidney showed normal architecture suggesting no morphological alterations. In conclusion, the oral administration of the crude methanolic bark extract of Bridelia micrantha and the fraction F<sub>6</sub> for 28 days at a dosage of up to 800 mg/kg did not induce toxicological damage in rats. From acute toxicity study, the median lethal dose (LD<sub>50</sub>) of the crude methanolic bark extract of Bridelia micrantha and the fraction F<sub>6</sub> was estimated to be more than 2000 mg/kg.展开更多
The stems and leaves of Mikania micrantha were successively extracted with petroleum ether, ethyl acetate and ethanol. In vitro and in vivo test method was adopted to deten＇nine the inhibition activity of three solve...The stems and leaves of Mikania micrantha were successively extracted with petroleum ether, ethyl acetate and ethanol. In vitro and in vivo test method was adopted to deten＇nine the inhibition activity of three solvent extracts against three plant pathogens. Growth rate method showed that ethyl acetate extract could significantly inhibit the mycelial growth of Botrytis circrea, Gtomerclla ciugulata and Fusarium bulbigeuum under the given concentration of 0.09 g/ml in dry sam- ple, and the inhibition rates were all greater than 90%. Organization test showed that the curative effect of petroleum ether extract against B. cirerea was 63.55% under the given concentration of 0.18 g/ml in dry sample, and the curative effect of ethanol extract was 71.47%. In the potting test against Erysiphe gramiuis, the curative effect of petroleum ether extract was 81.26%, while the curative effect of ethyl acetate extract was 62.07%.展开更多
Mikania micrantha Kunth is an invasive alien weed and known as a plant killer around the world.Accurately and rapidly identifying M.micrantha in the wild is important for monitoring its growth status,as this helps man...Mikania micrantha Kunth is an invasive alien weed and known as a plant killer around the world.Accurately and rapidly identifying M.micrantha in the wild is important for monitoring its growth status,as this helps management officials to take the necessary steps to devise a comprehensive strategy to control the invasive weed in the identified area.However,this approach still mainly depends on satellite remote sensing and manual inspection.The cost is high and the accuracy rate and efficiency are low.We acquired color images of the monitoring area in the wild environment using an Unmanned Aerial Vehicle(UAV)and proposed a novel network-MmNet-based on a deep Convolutional Neural Network(CNN)to identify M.micrantha in the images.The network consists of AlexNet Local Response Normalization(LRN),along with the GoogLeNet and continuous convolution of VGG inception models.After training and testing,the identification of 400 testing samples by MmNet is very good,with accuracy of 94.50%and time cost of 10.369 s.Moreover,in quantitative comparative analysis,the proposed MmNet not only has high accuracy and efficiency but also simple construction and outstanding repeatability.Compared with recently popular CNNs,MmNet is more suitable for the identification of M.micrantha in the wild.However,to meet the challenge of wild environments,more M.micrantha images need to be acquired for MmNet training.In addition,the classification labels need to be sorted in more detail.Altogether,this research provides some theoretical and scientific basis for the development of intelligent monitoring and early warning systems for M.micrantha and other invasive species.展开更多
Objective:To explore the hepatoprotective and anti-oxidant activities of the methanolic leaf extract of Bridelia micrantha(B.micrantha) on paracetamol induced liver damage in Wistar rats. Methods:Parameters were measu...Objective:To explore the hepatoprotective and anti-oxidant activities of the methanolic leaf extract of Bridelia micrantha(B.micrantha) on paracetamol induced liver damage in Wistar rats. Methods:Parameters were measured including alanine aminotransaminase(ALT),aspartate aminotransferase(AST),alkaline phosphatase(ALP),bilirubin and total protein.The anti-oxidant effects were studied using the 1,l-Diphenynl-2-Picrylhydrazyl(DPPH) and Ferric Reducing Antioxidant Power(FRAP) assay methods.Results:B.micrantha extract decreased the level of AST in the rats given PCM from(129.47±0.921) IU/L to(57.78±1.71) IU/L(P【0.05).This was lower than the value for Silymarin which was(59.92±1.41) IU/L.ALT concentration was reduced from (150.18±2.23) IU/L to(79.10±2.01) IU/L(P【0.05).ALP was reduced from(49.86±0.85) IU/L to(29.64±1.53) IU/L(P【0.05).Total bilirubin was reduced from(2.14±0.10 mg/dL) to(0.18±0.07) mg/dL (P【0.05) while total protein was increased from(4.26±0.30) mg/dL to(6.20±0.19) mg/dL(P【0.05). Concentrations ranging from 10 - 400μg/mL of B.micrantha were assayed for antioxidant activities.The DPPH assay showed 98%antioxidant activity at concentration of 400μg/mL. The FRAP values were 0.016,0.39,0.455,0.601 and 1.382μM at 10.50,100,200 and 400μg/ mL respectively.Conclusions:Results suggest that B.micrantha has hepatoprotective and anti oxidant potentials.However,further work involving fractionation needs to done to isolate the active compound responsible for the hepatoprotective activity.展开更多
[ Objective ] The paper was to understand distribution and damage of alien weed Mikania micramhaln in Huiyang District of China. [ Method ] The coverage, nearby water sources, surrounding plants and control status of ...[ Objective ] The paper was to understand distribution and damage of alien weed Mikania micramhaln in Huiyang District of China. [ Method ] The coverage, nearby water sources, surrounding plants and control status of M. micranthain under different habitats in Huiyang District were surveyed. [ Result] M. micrantha grew violently in the habitats of irrigation ditches, orchard, field edge and wasteland with the coverage ranging from 10% to 90%. It grew more seriously around water sources and was very likely to recur after control. The wild growth of M. micranthaln was harmful to local agriculture, forestry and fishery. The com- prehensive control measures combing artificial control, chemical control, biological control and ecological control should be adopted in different habitats. [ Conclusion] The study orovided basis for comorehensive control and invasion risk assessment of M. micranthain.展开更多
[Objective] The paper was to explore the herbicidal effects of Periconia heveae culture filtrate on Mikania micrantha. [Method] Through indoor bioassay method, the inhibition effects of culture filtrates of seven spec...[Objective] The paper was to explore the herbicidal effects of Periconia heveae culture filtrate on Mikania micrantha. [Method] Through indoor bioassay method, the inhibition effects of culture filtrates of seven species of plant disease fungi on seed germination and seedling growth of M. micrantha were studied, and the security of P. heveae culture filtrate on pepper （Capsicum annuum） and tomato （Solanum lycopersicum） was also evaluated. [Result] The culture filtrates of P. heveae had strong inhibition effects on seed germination and the growth of root, shoot and seedling of M. micrantha, and the inhibition rates were 72.7%, 93.0%, 32.4%, and 54.6% （fresh weight）, respectively. Security tests showed that culture filtrates of P. heveae were safe to seed germination and root and shoot growth of tomato, and the growth rate had no significant difference with control, but they inhibited seed germination of pepper. [Conclusion] As potential biological herbicide, the culture filtrate and metabolites of P. heveae is worthy of further development. .展开更多
Endophytic fungi were identified from different parts of the medicinal parasitic mistletoe Cladocolea micrantha and from its host Anacardium occidentale, suggesting a strict host-parasite relationship. Eight fungal en...Endophytic fungi were identified from different parts of the medicinal parasitic mistletoe Cladocolea micrantha and from its host Anacardium occidentale, suggesting a strict host-parasite relationship. Eight fungal endophytes were isolated and morphologically characterized. The ascomycete Guignardia mangiferae and strains of Mycelia sterilia were prevalent in the isolations. The unequivocal identification of Guignardia mangiferae at a probabilistic degree close to 100% was carried out by DNA extraction followed by PCR analyses of the ITS-1 and ITS-2 regions and comparison of the genetic sequence with the NCBI database.展开更多
The invasive plant Mikania micrantha Kunth(M.micrantha)from South America poses a significant threat to the stability and biodiversity of ecosystems.However,an effective and economical method to control M.micrantha is...The invasive plant Mikania micrantha Kunth(M.micrantha)from South America poses a significant threat to the stability and biodiversity of ecosystems.However,an effective and economical method to control M.micrantha is still lacking.RNA interference(RNAi)has been widely studied and applied in agriculture for trait improvement.Spray-induced gene silencing(SIGS)can produce RNAi silencing effects without introducing heritable modifications to the plant genome and is becoming a novel nontransformation strategy for plant protection.In this study,the genes encoding chlorophyll a/b-binding proteins were selected as targets of RNAi,based on high-throughput sequencing of M.micrantha transcriptome and bioinformatic analyses of sequence specificity.Three types of RNAi molecules,double-stranded RNA,RNAi nanomicrosphere,and short hairpin RNA(shRNA),with their corresponding short interfering RNA sequences were designed and synthesized for SIGS vector construction,from which each RNAi molecule was transcribed and extracted to be sprayed on M.micrantha leaves.Whereas water-treated control leaves remained green,leaves treated with RNAi molecules turned yellow and eventually wilted.Quantitative real-time PCR showed that the expression levels of target genes were significantly reduced in the RNAi-treated groups compared with those of the control,suggesting that all three types of RNAi herbicides effectively silenced the endogenous target genes,which are essential for the growth of M.micrantha.We also found that shRNA showed better silencing efficiency than the other two molecules.Taken together,our study successfully designed three types of RNAi-based herbicides that specifically silenced endogenous target genes and controlled the growth of M.micrantha.Moreover,we identified a gene family encoding chlorophyll a/b-binding proteins that is important for the growth and development of M.micrantha and could serve as potential targets for controlling the spread of M.micrantha.展开更多
基金funded by the National Natural Science Foundation of China(32072490)the National Key R&D Program of China(2021YFC2600100 and2021YFC2600101)the Agricultural Science and Technology Innovation Program,China。
文摘Mikania micrantha is a fast-growing global invasive weed species that causes severe damage to natural ecosystems and very large economic losses of forest and crop production.It has advantages in photosynthesis,including a similar net photosynthetic rate as C4 plants and a higher carbon fixation capacity.We used a combination of genomics and transcriptomics approaches to study the evolutionary mechanisms and circadian expression patterns of M.micrantha.In M.micrantha,16 positive selection genes focused on photoreaction and utilization of photoassimilates.In different tissues,98.1%of the genes associated with photoresponse had high expression in stems,and more than half of the genes of the C4 cycle had higher expression in stems than in leaves.In stomatal opening and closing,2 genes of carbonic anhydrase(CAs)had higher expression at 18:00 than at 8:00,and the slow anion channel 1(SLAC1)and high-leaf-temperature 1 kinase(HT1)genes were expressed at low levels at 18:00.In addition,genes associated with photosynthesis had higher expression levels at 7:00 and 17:00.We hypothesized that M.micrantha may undergo photosynthesis in the stem and flower organs and that some stomata of the leaves were opening at night by CO_(2)signals.In addition,its evolution may attenuate photoinhibition at high light intensities,and enhance more efficient of photosynthesis during low light intensity.And the tissue-specific photosynthetic types and different diurnal pattern of photosynthetic-related genes may contribute to its rapid colonization of new habitats of M.micrantha.
文摘[Objectives]The paper was to understand the occurrence and damage regularity of the invasive plant Mikania micrantha in Huadu District of Guangzhou.[Methods]The damage status of M.micranthFa in different forest lands and its annual growth dynamics were investigated by field investigation.[Results]With the change of canopy density from low to high,the occurrence degree of M.micrantha changed from high to low.The occurrence degree of M.micrantha in different forest land types was:abandoned orchard>wasteland>roadside greenbelt>waterside>forest edge>normally managed orchard.[Conclusions]M.micrantha enters the rapid growth period from March to May in spring,with the growth rate gradually slowing down after June.The result provides a theoretical basis and practical guidance for the prevention and control of M.micrantha.
文摘Bridelia micrantha, commonly known as coastal golden leaf, is a member of the family Phyllanthaceae. In preliminary studies nine fractions, named F1 - F9, were obtained by fractionating the crude methanol extract of the stem bark of Bridelia micrantha using column chromatographic techniques. The fraction F6 was the most active when tested for antibacterial activity. Thus, toxicity of this fraction was investigated for further use. The present study evaluated the acute and sub-chronic toxicity of the crude methanolic bark extract of Bridelia micrantha and its fraction. The acute toxicity was carried out according to the experimental protocol of Organization for Economic Co-operation and Development (OECD). The plant extract or the fraction F<sub>6</sub> was administered orally to female mice at a single dose of 2000 mg/kg and the animals were observed for any behavioral changes or mortality for 14 days. In the sub-chronic toxicity study, the extract and fraction were administered orally at 200, 400 and 800 mg/kg bw/day for 28 days to healthy Wistar rats. The general behavior and body weight of the rats were recorded daily. At the end of the experimental period, hematological and biochemical analyses, changes in vital organ weight (liver, lung, heart, spleen and kidney), and histopathological examination of the liver and kidney were performed. No mortality or adverse effects were noted at the 2000 mg/kg dose during the oral acute toxicity test. In the sub-chronic study, the crude methanolic bark extract of Bridelia micrantha and the fraction F<sub>6</sub> induced no mortality or treatment-related adverse effects on body weight, general behavior, relative organ weights, hematological and biochemical parameters. Histopathological examination of the liver and kidney showed normal architecture suggesting no morphological alterations. In conclusion, the oral administration of the crude methanolic bark extract of Bridelia micrantha and the fraction F<sub>6</sub> for 28 days at a dosage of up to 800 mg/kg did not induce toxicological damage in rats. From acute toxicity study, the median lethal dose (LD<sub>50</sub>) of the crude methanolic bark extract of Bridelia micrantha and the fraction F<sub>6</sub> was estimated to be more than 2000 mg/kg.
基金Supported by Special Research for National Public Service Sectors (Agriculture) (200903052)~~
文摘The stems and leaves of Mikania micrantha were successively extracted with petroleum ether, ethyl acetate and ethanol. In vitro and in vivo test method was adopted to deten＇nine the inhibition activity of three solvent extracts against three plant pathogens. Growth rate method showed that ethyl acetate extract could significantly inhibit the mycelial growth of Botrytis circrea, Gtomerclla ciugulata and Fusarium bulbigeuum under the given concentration of 0.09 g/ml in dry sam- ple, and the inhibition rates were all greater than 90%. Organization test showed that the curative effect of petroleum ether extract against B. cirerea was 63.55% under the given concentration of 0.18 g/ml in dry sample, and the curative effect of ethanol extract was 71.47%. In the potting test against Erysiphe gramiuis, the curative effect of petroleum ether extract was 81.26%, while the curative effect of ethyl acetate extract was 62.07%.
基金supported by the National Natural Science Foundation of China(3180111238)the Fund Project of the Key Laboratory of Integrated Pest Management on Crops in South China,Ministry of Agriculture and Rural Affairs,China(SCIPM2018-05)+2 种基金the Key Research and Development Program of Nanning,China(20192065)the Guangdong Science and Technology Planning Project,China(2017A020216022)the Industrial Development Fund Support Project of Dapeng District,Shenzhen,China(KY20180117)。
文摘Mikania micrantha Kunth is an invasive alien weed and known as a plant killer around the world.Accurately and rapidly identifying M.micrantha in the wild is important for monitoring its growth status,as this helps management officials to take the necessary steps to devise a comprehensive strategy to control the invasive weed in the identified area.However,this approach still mainly depends on satellite remote sensing and manual inspection.The cost is high and the accuracy rate and efficiency are low.We acquired color images of the monitoring area in the wild environment using an Unmanned Aerial Vehicle(UAV)and proposed a novel network-MmNet-based on a deep Convolutional Neural Network(CNN)to identify M.micrantha in the images.The network consists of AlexNet Local Response Normalization(LRN),along with the GoogLeNet and continuous convolution of VGG inception models.After training and testing,the identification of 400 testing samples by MmNet is very good,with accuracy of 94.50%and time cost of 10.369 s.Moreover,in quantitative comparative analysis,the proposed MmNet not only has high accuracy and efficiency but also simple construction and outstanding repeatability.Compared with recently popular CNNs,MmNet is more suitable for the identification of M.micrantha in the wild.However,to meet the challenge of wild environments,more M.micrantha images need to be acquired for MmNet training.In addition,the classification labels need to be sorted in more detail.Altogether,this research provides some theoretical and scientific basis for the development of intelligent monitoring and early warning systems for M.micrantha and other invasive species.
文摘Objective:To explore the hepatoprotective and anti-oxidant activities of the methanolic leaf extract of Bridelia micrantha(B.micrantha) on paracetamol induced liver damage in Wistar rats. Methods:Parameters were measured including alanine aminotransaminase(ALT),aspartate aminotransferase(AST),alkaline phosphatase(ALP),bilirubin and total protein.The anti-oxidant effects were studied using the 1,l-Diphenynl-2-Picrylhydrazyl(DPPH) and Ferric Reducing Antioxidant Power(FRAP) assay methods.Results:B.micrantha extract decreased the level of AST in the rats given PCM from(129.47±0.921) IU/L to(57.78±1.71) IU/L(P【0.05).This was lower than the value for Silymarin which was(59.92±1.41) IU/L.ALT concentration was reduced from (150.18±2.23) IU/L to(79.10±2.01) IU/L(P【0.05).ALP was reduced from(49.86±0.85) IU/L to(29.64±1.53) IU/L(P【0.05).Total bilirubin was reduced from(2.14±0.10 mg/dL) to(0.18±0.07) mg/dL (P【0.05) while total protein was increased from(4.26±0.30) mg/dL to(6.20±0.19) mg/dL(P【0.05). Concentrations ranging from 10 - 400μg/mL of B.micrantha were assayed for antioxidant activities.The DPPH assay showed 98%antioxidant activity at concentration of 400μg/mL. The FRAP values were 0.016,0.39,0.455,0.601 and 1.382μM at 10.50,100,200 and 400μg/ mL respectively.Conclusions:Results suggest that B.micrantha has hepatoprotective and anti oxidant potentials.However,further work involving fractionation needs to done to isolate the active compound responsible for the hepatoprotective activity.
基金Supported by Special Fund for Scientific Research in the Public Interest(201103027)Eleventh Five-Year National Science and Technology Support Project(2006BAD32B0103)
文摘[ Objective ] The paper was to understand distribution and damage of alien weed Mikania micramhaln in Huiyang District of China. [ Method ] The coverage, nearby water sources, surrounding plants and control status of M. micranthain under different habitats in Huiyang District were surveyed. [ Result] M. micrantha grew violently in the habitats of irrigation ditches, orchard, field edge and wasteland with the coverage ranging from 10% to 90%. It grew more seriously around water sources and was very likely to recur after control. The wild growth of M. micranthaln was harmful to local agriculture, forestry and fishery. The com- prehensive control measures combing artificial control, chemical control, biological control and ecological control should be adopted in different habitats. [ Conclusion] The study orovided basis for comorehensive control and invasion risk assessment of M. micranthain.
基金Supported by Research Special Project of Public Industry(Agriculture)(201103027)Control of Invasive Alien Species of MOA & International Cooperation Project of MOST(2011DFB30040)+1 种基金Key Project of Science andTechnology of Hainan Province(080149)Basic Scientific Research Expenses for Central Scientific Research Institutes in Environment and Plant Protection Institute,Chinese Academy of Tropical Agricultural Sciences(2009hzs1J018)
文摘[Objective] The paper was to explore the herbicidal effects of Periconia heveae culture filtrate on Mikania micrantha. [Method] Through indoor bioassay method, the inhibition effects of culture filtrates of seven species of plant disease fungi on seed germination and seedling growth of M. micrantha were studied, and the security of P. heveae culture filtrate on pepper （Capsicum annuum） and tomato （Solanum lycopersicum） was also evaluated. [Result] The culture filtrates of P. heveae had strong inhibition effects on seed germination and the growth of root, shoot and seedling of M. micrantha, and the inhibition rates were 72.7%, 93.0%, 32.4%, and 54.6% （fresh weight）, respectively. Security tests showed that culture filtrates of P. heveae were safe to seed germination and root and shoot growth of tomato, and the growth rate had no significant difference with control, but they inhibited seed germination of pepper. [Conclusion] As potential biological herbicide, the culture filtrate and metabolites of P. heveae is worthy of further development. .
文摘Endophytic fungi were identified from different parts of the medicinal parasitic mistletoe Cladocolea micrantha and from its host Anacardium occidentale, suggesting a strict host-parasite relationship. Eight fungal endophytes were isolated and morphologically characterized. The ascomycete Guignardia mangiferae and strains of Mycelia sterilia were prevalent in the isolations. The unequivocal identification of Guignardia mangiferae at a probabilistic degree close to 100% was carried out by DNA extraction followed by PCR analyses of the ITS-1 and ITS-2 regions and comparison of the genetic sequence with the NCBI database.
基金This research was financially supported by grants from the Shenzhen Science and Technology Program,China(Grant No.JCYJ20190808115005598)National Natural Science Foundation of China(Grant No.31801078)+1 种基金Guangdong Innovation Research Team Fun(Grant No.2014ZT05S078),Natural Science Foundation of SZU(Grant.No.2019080)the Undergraduate Academic Competition Project of Shenzhen University(Grant No.803-0000290846).
文摘The invasive plant Mikania micrantha Kunth(M.micrantha)from South America poses a significant threat to the stability and biodiversity of ecosystems.However,an effective and economical method to control M.micrantha is still lacking.RNA interference(RNAi)has been widely studied and applied in agriculture for trait improvement.Spray-induced gene silencing(SIGS)can produce RNAi silencing effects without introducing heritable modifications to the plant genome and is becoming a novel nontransformation strategy for plant protection.In this study,the genes encoding chlorophyll a/b-binding proteins were selected as targets of RNAi,based on high-throughput sequencing of M.micrantha transcriptome and bioinformatic analyses of sequence specificity.Three types of RNAi molecules,double-stranded RNA,RNAi nanomicrosphere,and short hairpin RNA(shRNA),with their corresponding short interfering RNA sequences were designed and synthesized for SIGS vector construction,from which each RNAi molecule was transcribed and extracted to be sprayed on M.micrantha leaves.Whereas water-treated control leaves remained green,leaves treated with RNAi molecules turned yellow and eventually wilted.Quantitative real-time PCR showed that the expression levels of target genes were significantly reduced in the RNAi-treated groups compared with those of the control,suggesting that all three types of RNAi herbicides effectively silenced the endogenous target genes,which are essential for the growth of M.micrantha.We also found that shRNA showed better silencing efficiency than the other two molecules.Taken together,our study successfully designed three types of RNAi-based herbicides that specifically silenced endogenous target genes and controlled the growth of M.micrantha.Moreover,we identified a gene family encoding chlorophyll a/b-binding proteins that is important for the growth and development of M.micrantha and could serve as potential targets for controlling the spread of M.micrantha.
