Evolution of specificity at the D14L signaling node for plant development and symbiosis

主题：农业与粮食安全了解D14L在基生植物古马药中的功能。KAI2/D14L在拟南芥和水稻的萌发、幼苗生长和与丛枝菌根（AM）真菌的有益关联中起核心作用，但D14L在基生植物中的功能尚不清楚。独脚金内酯（SLs）是一种调节AM真菌生长发育的植物激素。另一方面，卡瑞金斯（KARs）是在烟雾中发现的非生物化合物，可以刺激追火植物的种子发芽并影响幼苗生长。SLs和KARs的受体D14和D14L/KAI2是相似的。sl不敏感的d14突变体保留了被AM真菌定植的能力。相比之下，水稻D14L对于AM真菌的根感知和共生互作的启动是必不可少的。D14和D14L的共同进化起源解释了SL和KAR信号通路之间的显著相似之处，最终导致F-box蛋白DWARF3(D3)/MORE AXILLARY GROWTH （MAX2）的共同需求。KAR/ kl信号成分的同源物D14L、SMAX1和D3存在于所有陆地植物中，而sl信号蛋白D14和D53不存在于基生植物中。因此，通过D14-D3-D53的典型SL信号是胚胎植物的创新。尽管如此，在基生植物中发现了SLs，它们确实对外源SL类似物有发育反应，可能是通过D14L介导的。似乎，d14l介导的机制可能对早期陆地植物发育和AM共生相互作用很重要。我们将利用我们的集体专业知识来研究D14L在基生陆地植物和火适应物种中的作用。(A)底苔属植物包括遗传易感的地苔科植物。我们将把CRISPR/Cas9技术应用于菌根物种古马钱提亚（Marchantia paleacea），验证D14L是植物发育和AM在基生植物共生所必需的假设。(B)为了评估D14L在整个植物界的共生作用是否保守，我们将水稻hebibaAOC与稻瘟霉和稻瘟霉的D14L基因进行遗传互补。在非菌根拟南芥中，引入多形地豆（Marchantia polymorpha） D14L不能补充kai2的发育表型。如果在水稻AM信号中也有类似的观察结果，我们将把M. paleacea D3和SMAX1引入hebibaAOC，并杂交到表达mpald14l的细胞系中，以验证其功能守恒性。同样，在目标2A中鉴定出的具有kl配体偏好的D14L变异将通过水稻D14L的工程等效替换来检测其介导共生信号的能力。基因D14L被破坏后菌根菌和古马药的转录组和蛋白质组分析。这些数据集还将与从谷物物种收集的转录组学/蛋白质组学数据进行比较。-通过生物成像和评估数量性状的统计分析来评估真菌的定植。

Theme: Agriculture and Food SecurityUnravel the function of D14L in the basal plant Marchantia paleacea. KAI2/D14L plays central roles in germination, seedling growth, and beneficial associations with arbuscular mycorrhizal (AM) fungi in Arabidopsis and rice, but the function of D14L in basal plants remains unknown.Strigolactones (SLs) are plant hormones that regulate plant development and growth of AM fungi. Karrikins (KARs), on the other hand, are abiotic compounds found in smoke that stimulate seed germination of fire-chasing plants and influence seedling growth. The receptors for SLs and KARs, D14 and D14L/KAI2, are paralogs. SL-insensitive d14 mutants retain the ability to be colonized by AM fungi. In contrast, Rice D14L is indispensable for root-perception of AM fungi and for initiation of the symbiotic interaction. The common evolutionary origin of D14 and D14L explains the remarkable parallels between the SL and KAR signaling pathways, which culminate in a shared requirement for the F-box protein DWARF3(D3)/MORE AXILLARY GROWTH (MAX2). Orthologues of the KAR/KL-signaling components D14L, SMAX1 and D3 occur in all land plants, whereas the SL-signaling proteins D14 and D53 are absent from basal plants. Therefore, canonical SL signaling via D14-D3-D53 was an innovation of Embryophyta. Nonetheless SLs are found in basal plants, which indeed have developmental responses to exogenous SL analogs, possibly mediated via D14L. Plausibly, a D14L-mediated mechanism may have been important for early land plant development and AM symbiotic interactions. We will use our collective expertise to investigate the role of D14L in basal land plants and fire-adapted species.(A) The basal liverworts include the genetically tractable Marchantiaceae. We will apply the CRISPR/Cas9 technology to the mycorrhizal species Marchantia paleacea to test the hypothesis that D14L is required for plant development and AM symbiosis in basal plants. (B) To assess whether the role of D14L in symbiosis is conserved across the plant kingdom, genetic complementation of rice hebibaAOC with both M. paleacea and N. attenuata D14L genes will be performed. In non-mycorrhizal Arabidopsis introduction of Marchantia polymorpha D14L failed to complement kai2 developmental phenotypes. If similar observations were made for AM signaling in rice, M. paleacea D3 and SMAX1 will be introduced into hebibaAOC and crossed to the MpalD14L-expressing line to verify functional conservation. Similarly, D14L variants identified in Objective 2A to confer preference for KL-ligands will be examined for their ability to mediate symbiosis signaling by engineering equivalent substitutions of rice D14L.ENWW:- Transcriptome and proteome analysis of Mycorrhiza and Marchantia paleacea upon disruption of the gene D14L. These datasets will additionally be compared to transcriptomics/proteomics data collected from cereal species.- Assessment of mycorrhizal colonization of M. paleacea via biological imaging and statistical analysis of the quantitative traits assessed.