Rorippa indica is a wild oilseed crop of Brassicaceae with good environmental adaptability and strong stress resistance.This plant has become an important wild relative species for rapeseed(Brassica napus L.)and is us...Rorippa indica is a wild oilseed crop of Brassicaceae with good environmental adaptability and strong stress resistance.This plant has become an important wild relative species for rapeseed(Brassica napus L.)and is used to improve its agronomic traits,with important development and utilization value.However,the research of R.indica genetics is still lacking.And no mitochondrial genome(mitogenome)in the genus Rorippa has been expounded.To analyze the structural characteristics of the R.indica mitogenome,second-generation and third-generation sequencing techniques were made to assemble its mitogenome.The results showed that its mitogenome is composed of a single master circle DNA molecule,with 59 genes(33 protein-coding,23 tRNA,and 3 ribosomal RNA genes)annotated.The length of the circular genome is 219,775 bp,with aGCcontent of 45.24%.Themitochondrial genome contains 55 SSRs,17 tandem repeats,and 252 scattered repeat sequences,with scattered repeat sequences accounting for 77.78%.The top two codons with the highest expression levels are TTT and AUU.Moreover,377 RNA editing sites were forecasted in the R.indica mitogenome.And 22 collinear gene fragments were discriminated in the R.indica chloroplast andmitogenomes,with a total 13,153 bp length,accounting for 4.08%of the mitogenome sequence.The longest gene migration fragment is 2186 bp,and the shortest fragment is 42 bp.Furthermore,12 genes undergo complete migration between the two genomes,and 10 genes undergo partial migration.Systematic evolutionary analysis shows that R.indica and Brassica napus are grouped,indicating a close genetic relationship between the two.Herein,the R.indica mitogenome was sequenced and annotated,and it was compared with other Brassicaceae mitogenomes.A genomic data foundation was supplied for elucidating the R.indica origin and evolution.展开更多
Polyploids contribute substantially to plant evolution and biodiversity;however,the mechanisms by which they succeed are still unclear.According to the polyploid adaptation hypothesis,successful polyploids spread by r...Polyploids contribute substantially to plant evolution and biodiversity;however,the mechanisms by which they succeed are still unclear.According to the polyploid adaptation hypothesis,successful polyploids spread by repeated adaptive responses to new environments.Here,we tested this hypothesis using two tetraploid yellowcresses(Rorippa),the endemic Rorippa elata and the widespread Rorippa palustris,in the temperate biodiversity hotspot of the Hengduan Mountains.Speciation modes were resolved by phylogenetic modeling using 12 low-copy nuclear loci.Phylogeographical patterns were then examined using haplotypes phased from four plastid and ITS markers,coupled with historical niche reconstruction by ecological niche modeling.We inferred the time of hybrid origins for both species as the mid-Pleistocene,with shared glacial refugia within the southern Hengduan Mountains.Phylogeographic and ecological niche reconstruction indicated recurrent northward colonization by both species after speciation,possibly tracking denuded habitats created by glacial retreat during interglacial periods.Common garden experiment involving perennial R.elata conducted over two years revealed significant changes in fitness-related traits across source latitudes or altitudes,including latitudinal increases in survival rate and compactness of plant architecture,suggesting gradual adaptation during range expansion.These findings support the polyploid adaptation hypothesis and suggest that the spread of polyploids was aided by adaptive responses to environmental changes during the Pleistocene.Our results thus provide insight into the evolutionary success of polyploids in high-altitude environments.展开更多
North American lake cress, Rorippa aquatica (Eaton) EJ Palmer & Steyermark (Brassicaceae), is listed as an endangered or threatened species. Lake cress shows heterophyllic changes in leaf form in response to the s...North American lake cress, Rorippa aquatica (Eaton) EJ Palmer & Steyermark (Brassicaceae), is listed as an endangered or threatened species. Lake cress shows heterophyllic changes in leaf form in response to the surrounding environment. Therefore, this species has received considerable attention from ecological and morphological perspectives. However, its phylogenetic position and taxonomic status have long been a subject of debate. To analyze the phylogenetic relationship of lake cress, we investigated chloroplast DNA sequences from 17 plant species. The results of phylogenetic reconstruction performed using trnL intron, trnG (GCC)-trnM (CAU), and psbC-trnS (UGA) indicated that lake cress is a member of Rorippa. Moreover, we found that the chromosome number of lake cress is 2n = 30. This result indicated that lake cress might have originated from aneuploidy of triploid species or via intergeneric crossing. Taken together, our results suggest an affinity between lake cress and Rorippa at the molecular level, indicating that lake cress should be treated as Rorippa aquatica (Eaton) EJ Palmer & Steyermark.展开更多
Rorippa globosa has been identified as a newly-found Cd-hyperaccumulating species.In the present study,growth responses of Rorippa globosa and its accumulation characteristics of Cd and As were examined under joint st...Rorippa globosa has been identified as a newly-found Cd-hyperaccumulating species.In the present study,growth responses of Rorippa globosa and its accumulation characteristics of Cd and As were examined under joint stress of Cd and As.The results showed that Cd and As had an antagonistic effect on enhancing the growth of Rorippa globosa plants and Cd uptake and accumulation under the low concentration Cd and As treatments.When the concentra-tion of Cd in the soil was 10 mg/kg and the concentration of As was 50 mg/kg,the highest growing height of the plant was up to 35.9 cm and the dry weight of the shoots was up to 2.2 g/pot,respectively.Meanwhile,the accumulation of Cd in the leaves under the joint stress was higher than that at the same level under single Cd pollution.However,there were synergic adverse effects on plant growth and Cd uptake under the combined pollution from a high concentration of Cd and As.Meanwhile,the accumulation of As in the roots was greater than that in the shoots,the translocation factor(TF)was h0.3 and the bioaccumulation factor(BF)was h0.6,thus showing that Rorippa globosa had an excluding effect on As uptake.These results confirmed that Rorippa globosa had a strong tolerant ability to the joint stress of Cd and As,and the potential for phytoremediation of soils contaminated by Cd and As.展开更多
基金supported by the Jiangxi Province Higher Education Teaching Research Project(JXJG-22-23-3,NSJG-21-25)Jiangxi Province Key Laboratory of Oil Crops Biology(YLKFKT202203).
文摘Rorippa indica is a wild oilseed crop of Brassicaceae with good environmental adaptability and strong stress resistance.This plant has become an important wild relative species for rapeseed(Brassica napus L.)and is used to improve its agronomic traits,with important development and utilization value.However,the research of R.indica genetics is still lacking.And no mitochondrial genome(mitogenome)in the genus Rorippa has been expounded.To analyze the structural characteristics of the R.indica mitogenome,second-generation and third-generation sequencing techniques were made to assemble its mitogenome.The results showed that its mitogenome is composed of a single master circle DNA molecule,with 59 genes(33 protein-coding,23 tRNA,and 3 ribosomal RNA genes)annotated.The length of the circular genome is 219,775 bp,with aGCcontent of 45.24%.Themitochondrial genome contains 55 SSRs,17 tandem repeats,and 252 scattered repeat sequences,with scattered repeat sequences accounting for 77.78%.The top two codons with the highest expression levels are TTT and AUU.Moreover,377 RNA editing sites were forecasted in the R.indica mitogenome.And 22 collinear gene fragments were discriminated in the R.indica chloroplast andmitogenomes,with a total 13,153 bp length,accounting for 4.08%of the mitogenome sequence.The longest gene migration fragment is 2186 bp,and the shortest fragment is 42 bp.Furthermore,12 genes undergo complete migration between the two genomes,and 10 genes undergo partial migration.Systematic evolutionary analysis shows that R.indica and Brassica napus are grouped,indicating a close genetic relationship between the two.Herein,the R.indica mitogenome was sequenced and annotated,and it was compared with other Brassicaceae mitogenomes.A genomic data foundation was supplied for elucidating the R.indica origin and evolution.
基金supported by the National Natural Science Foundation of China(31800177,32170224,and U1802242)the Strategic Priority Research Program of Chinese Academy of Sciences(XDB31000000)+2 种基金T-S.H.is also supported by the Youth Innovation Promotion Association CAS(2020391)China Scholarship Council(201804910061)CAS Light of West China Program.We acknowledge Ya-Long Guo at the Institute of Botany CAS for providing Capsella rubella seeds and revising the manuscript.
文摘Polyploids contribute substantially to plant evolution and biodiversity;however,the mechanisms by which they succeed are still unclear.According to the polyploid adaptation hypothesis,successful polyploids spread by repeated adaptive responses to new environments.Here,we tested this hypothesis using two tetraploid yellowcresses(Rorippa),the endemic Rorippa elata and the widespread Rorippa palustris,in the temperate biodiversity hotspot of the Hengduan Mountains.Speciation modes were resolved by phylogenetic modeling using 12 low-copy nuclear loci.Phylogeographical patterns were then examined using haplotypes phased from four plastid and ITS markers,coupled with historical niche reconstruction by ecological niche modeling.We inferred the time of hybrid origins for both species as the mid-Pleistocene,with shared glacial refugia within the southern Hengduan Mountains.Phylogeographic and ecological niche reconstruction indicated recurrent northward colonization by both species after speciation,possibly tracking denuded habitats created by glacial retreat during interglacial periods.Common garden experiment involving perennial R.elata conducted over two years revealed significant changes in fitness-related traits across source latitudes or altitudes,including latitudinal increases in survival rate and compactness of plant architecture,suggesting gradual adaptation during range expansion.These findings support the polyploid adaptation hypothesis and suggest that the spread of polyploids was aided by adaptive responses to environmental changes during the Pleistocene.Our results thus provide insight into the evolutionary success of polyploids in high-altitude environments.
文摘North American lake cress, Rorippa aquatica (Eaton) EJ Palmer & Steyermark (Brassicaceae), is listed as an endangered or threatened species. Lake cress shows heterophyllic changes in leaf form in response to the surrounding environment. Therefore, this species has received considerable attention from ecological and morphological perspectives. However, its phylogenetic position and taxonomic status have long been a subject of debate. To analyze the phylogenetic relationship of lake cress, we investigated chloroplast DNA sequences from 17 plant species. The results of phylogenetic reconstruction performed using trnL intron, trnG (GCC)-trnM (CAU), and psbC-trnS (UGA) indicated that lake cress is a member of Rorippa. Moreover, we found that the chromosome number of lake cress is 2n = 30. This result indicated that lake cress might have originated from aneuploidy of triploid species or via intergeneric crossing. Taken together, our results suggest an affinity between lake cress and Rorippa at the molecular level, indicating that lake cress should be treated as Rorippa aquatica (Eaton) EJ Palmer & Steyermark.
基金This work was support by the National Natural Science Foundation of China as an overseas distinguished young scholars award(Grant No.20428707)as a key project(Grant No.20337010)by the Sino-Russia Joint Research Center on Natural Resources and Eco-Environmental Sciences.
文摘Rorippa globosa has been identified as a newly-found Cd-hyperaccumulating species.In the present study,growth responses of Rorippa globosa and its accumulation characteristics of Cd and As were examined under joint stress of Cd and As.The results showed that Cd and As had an antagonistic effect on enhancing the growth of Rorippa globosa plants and Cd uptake and accumulation under the low concentration Cd and As treatments.When the concentra-tion of Cd in the soil was 10 mg/kg and the concentration of As was 50 mg/kg,the highest growing height of the plant was up to 35.9 cm and the dry weight of the shoots was up to 2.2 g/pot,respectively.Meanwhile,the accumulation of Cd in the leaves under the joint stress was higher than that at the same level under single Cd pollution.However,there were synergic adverse effects on plant growth and Cd uptake under the combined pollution from a high concentration of Cd and As.Meanwhile,the accumulation of As in the roots was greater than that in the shoots,the translocation factor(TF)was h0.3 and the bioaccumulation factor(BF)was h0.6,thus showing that Rorippa globosa had an excluding effect on As uptake.These results confirmed that Rorippa globosa had a strong tolerant ability to the joint stress of Cd and As,and the potential for phytoremediation of soils contaminated by Cd and As.
