Postembryonic organogenesis is critical for plant development.Underground,lateral roots(LRs)form the bulk of mature root systems,yet the ontogeny of the LR primordium(LRP)is not clear.In this study,we performed the si...Postembryonic organogenesis is critical for plant development.Underground,lateral roots(LRs)form the bulk of mature root systems,yet the ontogeny of the LR primordium(LRP)is not clear.In this study,we performed the single-cell RNA sequencing through the first four stages of LR formation in Arabidopsis.Our analysis led to a model in which a single group of precursor cells,with a cell identity different from their pericycle origins,rapidly reprograms and splits into a mixed ground tissue/stem cell niche fate and a vascular precursor fate.The ground tissue and stem cell niche fates soon separate and a subset of more specialized vascular cells form sucrose transporting phloem cells that appear to connect to the primary root.We did not detect cells resembling epidermis or root cap,suggesting that outer tissues may form later,preceding LR emergence.At this stage,some remaining initial precursor cells form the primordium flanks,while the rest create a reservoir of pluripotent cells that are able to replace the LR if damaged.Laser ablation of the central and lateral LRP regions showed that remaining cells restart the sequence of tissue initiation to form a LR.Collectively,our study reveals an ontological hierarchy for LR formation with an early and sequential split of main root tissues and stem cells.展开更多
基金funded by the Ministerio de Economia y Competitividad(MINECO)of Spain and ERDF(grants BFU2016-80315-P and PID2019-111523GB-I00 to M.A.M.-R)by the Comunidad de Madrid(CM)and Uni-versidad Politecnica de Madrid(UPM+6 种基金grant APOYO_JOVENE-S_2Y36R7_20_TRG6W7[Plant_Stem]to P.P.-G.)the"Severo Ochoa(SO)Program for Centers of Excellence in R&D"from the Agencia Estatal de Investigacion of Spain[SEV-2016-0672(2017-2021)]to MAM.-R and P.P.-G via the CBGPby the National Institutes of Health(grant 1R35GM136362)National Science Foundation(grant 1934388)to K.D.B.L.S.-R.supported by FPI contracts(BES-2017-080155 and BES-2014-068852,respectively)from MINECOby Programa Atraccion Talento from CM(2017-T2/BIO-3453)by a Juan de la Cierva contract from MINECO(FJCI-2016-28607).
文摘Postembryonic organogenesis is critical for plant development.Underground,lateral roots(LRs)form the bulk of mature root systems,yet the ontogeny of the LR primordium(LRP)is not clear.In this study,we performed the single-cell RNA sequencing through the first four stages of LR formation in Arabidopsis.Our analysis led to a model in which a single group of precursor cells,with a cell identity different from their pericycle origins,rapidly reprograms and splits into a mixed ground tissue/stem cell niche fate and a vascular precursor fate.The ground tissue and stem cell niche fates soon separate and a subset of more specialized vascular cells form sucrose transporting phloem cells that appear to connect to the primary root.We did not detect cells resembling epidermis or root cap,suggesting that outer tissues may form later,preceding LR emergence.At this stage,some remaining initial precursor cells form the primordium flanks,while the rest create a reservoir of pluripotent cells that are able to replace the LR if damaged.Laser ablation of the central and lateral LRP regions showed that remaining cells restart the sequence of tissue initiation to form a LR.Collectively,our study reveals an ontological hierarchy for LR formation with an early and sequential split of main root tissues and stem cells.
