DNA-segment copy number variations(DSCNVs),such as deletions and duplications,are important sources of genomic structural variation.However,the types and sizes of DSCNVs,as well as their genome-wide distribution and p...DNA-segment copy number variations(DSCNVs),such as deletions and duplications,are important sources of genomic structural variation.However,the types and sizes of DSCNVs,as well as their genome-wide distribution and potential functions,are poorly understood in wheat.Here,we identified 198985 DSCNVs by investigating 491 genomes of common wheat and found that they account for 20%of the entire genome.Interestingly,approximately 38%of genes are linked to DSCNVs.The number of DSCNVs within each accession ranges from 47366 to 96342,and their total sizes vary from 421.3 to 1267.9 Mb.We found that 957 and 1304 DSCNVs have been favored by breeders in China and the United States,respectively.By conducting DSCNV-based genome-wide association studies for the principal components of plant developmental and yield-component traits,we identified 34 loci as directly or indirectly involved in controlling the formation of multiple traits.Notably,a newly discovered DSCNV covering TaFT-D1 is significantly associated with flowering time and other agronomic traits.Overall,our findings highlight the potential of DSCNVs to drive fundamental discoveries in plant science.The comprehensive DSCNV map and the DSCNV-associated genes will also facilitate future research efforts to improve wheat yield,quality,and adaptation.展开更多
Plants have evolved sophisticated genetic networks to regulate iron （Fe） homeostasis for their survival. Several classes of plant hormones including jasmonic acid （JA） have been shown to be involved in regulating ...Plants have evolved sophisticated genetic networks to regulate iron （Fe） homeostasis for their survival. Several classes of plant hormones including jasmonic acid （JA） have been shown to be involved in regulating the expression of iron uptake and/or deficiency-responsive genes in plants. However, the molecular mechanisms by which JA regulates iron uptake remain unclear. In this study, we found that JA negatively modulates iron uptake by downregulating the expression of FIT （bHLH29）, bHLH38, bHLH39, bHLHIO0, and bHLHI01 and promoting the degradation of FIT protein, a key regulator of iron uptake in Arabidopsis. We further demonstrated that the subgroup IVa bHLH proteins, bHLH18, bHLH19, bHLH20, and bHLH25, are novel interactors of FIT, which promote JA-induced FIT protein degradation. These four IVa bHLHs function redundantly to antagonize the activity of the Ib bHLHs （such as bHLH38） in regulating FIT protein stability under iron deficiency. The four IVa bHLH genes are primarily expressed in roots, and are inducible by JA treatment. Moreover, we found that MYC2 and JAR1, two critical components of the JA signaling pathway, play critical roles in mediating JA suppression of the expression of FIT and Ib bHLH genes, whereas they differentially modulate the expression of bHLH18, bHLH19, bHLH20, and bHLH25 to regulate FIT accumulation under iron deficiency. Taken together, these results indicate that by transcriptionally regulating the expression of different sets of bHLH genes JA signaling promotes FIT degradation, resulting in reduced expression of iron-uptake genes, IRT1 and FRO2, and increased sensitivity to iron deficiency. Our data suggest that there is a multilayered inhibition of iron-deficiency response in the presence JA in Arabidopsis.展开更多
Iron is an essential microelement for plant growth.After uptake from the soil,iron is chelated by ligands and translocated from roots to shoots for sub-sequent utilization.However,the number of ligands in-volved in ir...Iron is an essential microelement for plant growth.After uptake from the soil,iron is chelated by ligands and translocated from roots to shoots for sub-sequent utilization.However,the number of ligands in-volved in iron chelation is unclear.In this study,we identified and demonstrated that GLU1,which encodes a ferredoxin-dependent glutamate synthase,was involved in iron homeostasis.First,the expression of GLU1 was strongly induced by iron deficiency condition.Second,lesion of GLU1 results in reduced transcription of many iron-deficiency-responsive genes in roots and shoots.The mutant plants revealed a decreased iron concentration in the shoots,and displayed severe leaf chlorosis under the condition of Fe limitation,compared to wild-type.Third,the product of GLU1,glutamate,could chelate iron in vivo and promote iron transportation.Last,we also found that supplementation of glutamate in the medium can alleviate cadmium toxicity in plants.Overall,our results provide evidence that GLU1 is involved in iron homeo-stasis through affecting glutamate synthesis under iron deficiency conditions in Arabidopsis.展开更多
基金supported by the National Natural Science Foundation of China(grant nos.31991211,31921005,and 32201745)the Strategic Pri-ority Research Program of the Chinese Academy of Sciences(XDA24010104)+1 种基金the Hainan Seed Industry Laboratory(B23C1000402)the Major Basic Research Program of Shandong Natural Science Foundation(ZR2019ZD15).
文摘DNA-segment copy number variations(DSCNVs),such as deletions and duplications,are important sources of genomic structural variation.However,the types and sizes of DSCNVs,as well as their genome-wide distribution and potential functions,are poorly understood in wheat.Here,we identified 198985 DSCNVs by investigating 491 genomes of common wheat and found that they account for 20%of the entire genome.Interestingly,approximately 38%of genes are linked to DSCNVs.The number of DSCNVs within each accession ranges from 47366 to 96342,and their total sizes vary from 421.3 to 1267.9 Mb.We found that 957 and 1304 DSCNVs have been favored by breeders in China and the United States,respectively.By conducting DSCNV-based genome-wide association studies for the principal components of plant developmental and yield-component traits,we identified 34 loci as directly or indirectly involved in controlling the formation of multiple traits.Notably,a newly discovered DSCNV covering TaFT-D1 is significantly associated with flowering time and other agronomic traits.Overall,our findings highlight the potential of DSCNVs to drive fundamental discoveries in plant science.The comprehensive DSCNV map and the DSCNV-associated genes will also facilitate future research efforts to improve wheat yield,quality,and adaptation.
基金This work was supported by the Ministry of Agriculture of China （grant no. 2016ZX08009003-005） and the National Natural Science Foundation of China （grant no. 31471930）.
文摘Plants have evolved sophisticated genetic networks to regulate iron （Fe） homeostasis for their survival. Several classes of plant hormones including jasmonic acid （JA） have been shown to be involved in regulating the expression of iron uptake and/or deficiency-responsive genes in plants. However, the molecular mechanisms by which JA regulates iron uptake remain unclear. In this study, we found that JA negatively modulates iron uptake by downregulating the expression of FIT （bHLH29）, bHLH38, bHLH39, bHLHIO0, and bHLHI01 and promoting the degradation of FIT protein, a key regulator of iron uptake in Arabidopsis. We further demonstrated that the subgroup IVa bHLH proteins, bHLH18, bHLH19, bHLH20, and bHLH25, are novel interactors of FIT, which promote JA-induced FIT protein degradation. These four IVa bHLHs function redundantly to antagonize the activity of the Ib bHLHs （such as bHLH38） in regulating FIT protein stability under iron deficiency. The four IVa bHLH genes are primarily expressed in roots, and are inducible by JA treatment. Moreover, we found that MYC2 and JAR1, two critical components of the JA signaling pathway, play critical roles in mediating JA suppression of the expression of FIT and Ib bHLH genes, whereas they differentially modulate the expression of bHLH18, bHLH19, bHLH20, and bHLH25 to regulate FIT accumulation under iron deficiency. Taken together, these results indicate that by transcriptionally regulating the expression of different sets of bHLH genes JA signaling promotes FIT degradation, resulting in reduced expression of iron-uptake genes, IRT1 and FRO2, and increased sensitivity to iron deficiency. Our data suggest that there is a multilayered inhibition of iron-deficiency response in the presence JA in Arabidopsis.
基金This work was supported by the National Key Research and Development Program of China(2016YFD0100706)the National Natural Science Foundation of China(31870225).
文摘Iron is an essential microelement for plant growth.After uptake from the soil,iron is chelated by ligands and translocated from roots to shoots for sub-sequent utilization.However,the number of ligands in-volved in iron chelation is unclear.In this study,we identified and demonstrated that GLU1,which encodes a ferredoxin-dependent glutamate synthase,was involved in iron homeostasis.First,the expression of GLU1 was strongly induced by iron deficiency condition.Second,lesion of GLU1 results in reduced transcription of many iron-deficiency-responsive genes in roots and shoots.The mutant plants revealed a decreased iron concentration in the shoots,and displayed severe leaf chlorosis under the condition of Fe limitation,compared to wild-type.Third,the product of GLU1,glutamate,could chelate iron in vivo and promote iron transportation.Last,we also found that supplementation of glutamate in the medium can alleviate cadmium toxicity in plants.Overall,our results provide evidence that GLU1 is involved in iron homeo-stasis through affecting glutamate synthesis under iron deficiency conditions in Arabidopsis.
