Dimorphic fruits, seeds and seedlings as adaptation mechanisms to abiotic stress in unpredictable environments

高等植物的传播单位--散生孢子，这里指的是果实和种子--支持后代的分布和早期生活史。SeedAdapt项目的目的是阐明在一年生植物物种中进化的果实、种子和幼苗特征的分子机制，以适应不断变化和不可预测的环境。尽管这些特征是食品质量和安全以及生态系统命运的基石，但对包括高温和干旱在内的非生物胁迫适应机制的分子和发育生物多样性了解甚少。为了对这一重要的适应机制提供新的见解，我们的跨学科和综合项目利用在一年生十字花科植物上发育的独特的“二形散布孢子(DD)”作为休眠对冲策略。种子-一线孢子综合症(SDS)类似于拟南芥等杂草的默认途径：裂开的果实以非深度休眠的方式分散种子，这些种子在吸胀时形成粘液，在萌发过程中首先出现带有胚根的胚胎。果实-一线孢子综合征(FDS)构成了一种新的途径：不裂的果实散布在含有深度休眠的非粘性种子中，在萌发过程中，胚胎首先出苗时带有子叶。我们将比较两个适应不同气候的阿拉伯风藤属材料在三个敏感过程中对非生物胁迫的响应：(1)繁殖；(2)萌发；(3)幼苗生长。对于二晶型一水硬铝石的形成，我们将研究取决于亲本环境的SDS/FDS-比率，执行扩散基因的进化比较，并研究与症状和胁迫相关的硫代葡萄糖苷模式(一水硬铝石草食性)。二形性一线孢子的荷尔蒙、表观基因组和转录本提供了‘综合症x胁迫记忆’，它将以一种比较的方式被量化，并与二形性幼苗的胁迫生理模型、种子生物力学和生长成像相结合。Ae.阿拉伯基因组序列和RNA-Seq生物信息学管道是可用的。“综合症x应激记忆”数据的比较将提供差异表达的基因和不同的表观遗传标记。他们的目标分析将扩展到几个埃西奥马种群/物种，以及通过系统基因组学(例如，启动子元件)和作物和模式中的跨物种反向遗传学。我们将对SDS和FDS进行正向和反向遗传，以分离单个性状，包括利用已有的重组自交系进行EMS突变筛选和QTL分析，并建立遗传转化和资源。我们建议，研究果实、种子和幼苗性状多样性的调控基础是整合新技术和互补专业知识的理想选择，以便研究一个在生态学、进化、种业和作物育种中具有极其重要的领域。

Higher plant dispersal units - diaspores, here: fruits and seeds - support the distribution and early life history of the progeny. The aim of the SeedAdapt project is to elucidate molecular mechanisms of fruit, seed and seedling traits that evolved in annual plant species as adaptations to changing and unpredictable environments. Although these traits are cornerstones for food quality and safety as well as for the fate of ecosystems, the molecular and developmental biodiversity of mechanisms underlying the adaptation to abiotic stresses including heat and drought are only poorly understood. To provide novel insight into this important adaptation mechanism, our interdisciplinary and integrative project utilizes the distinct 'dimorphic diaspores (DD)' that develop on the same plant of annual Aethionema species (Brassicaceae) as dormancy bet-hedging strategy. The 'Seed-Diaspore Syndrome (SDS)' resembles the 'default pathway' of weeds like Arabidopsis: dehiscent fruits disperse seeds with non-deep dormancy, these seeds form mucilage upon imbibition, and embryos emerge with radicles first during germination. The 'Fruit-Diaspore Syndrome (FDS)' constitutes a 'novel pathway': indehiscent fruits are dispersed that contain non-mucilaginous seeds with deep dormancy, and embryos emerge with cotyledons first during germination. We will compare SDS and FDS of two Aethionema arabicum accessions adapted to distinct climates, for their responses to abiotic stress during three sensitive processes: (1) reproduction; (2) germination; and (3) seedling growth. For the dimorphic diaspore formation we will investigate the SDS/FDS-ratios depending on the parental environment, perform an evolutionary comparison of dispersal genes, and study syndrome- and stress-related glucosinolate patterns (diaspore herbivory). The dimorphic diaspores' hormonomes, epigenomes, and transcriptomes provide 'syndrome x stress memories' which will be quantified in a comparative manner and integrated with stress physiology modelling, seed biomechanics, and growth imaging of dimorphic seedlings. The Ae. arabicum genome sequence and a RNA-Seq bioinformatics pipeline are available. The comparison of the 'syndrome x stress memory' data will provide differentially expressed genes and distinct epigenetic markers. Their targeted analyses will be extended across several Aethionema populations/species, as well as by phylogenomics (e.g. promoter elements) and cross-species reverse-genetics in crops and models. We will conduct forward and reverse genetics of SDS and FDS to separate individual traits, including EMS-mutant screens and QTL analyses using already existing RILs, and we will establish genetic transformation and resources. We propose that investigating the regulatory basis of fruit, seed, and seedling trait diversity is ideal for integrating new technologies and complementary expertise in order to study a field with utmost importance in ecology, evolution, seed industry and crop breeding.