Evolution of lipid droplet-associated proteins and their role in drought resistance

脂滴相关蛋白的进化及其在抗旱中的作用

• 批准号: 528045595
• 负责人: Professor Dr. Till Ischebeck
• 金额: --
• 依托单位: Arbeitsgruppe Plant Biochemistry and Biotechnology
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/528045595?language=en
• 关键词: Evolution; lipid; droplet; associated; proteins

Drought is a prime stressor that plants had to overcome in their conquer of land. Most land plants are able to adapt to drought on the cellular level. Furthermore, they are able to produce desiccation tolerant cells and tissues as part of their reproductive cycle such as seeds, pollen and spores. However, many streptophyte algae are also displaying high stress resilience. While it is likely that drought resistance evolved several times independently, it is also likely that these independent origins of desiccation tolerance are underpinned by similar strategies and the co-option of existing regulatory programs for resilience. Common to both drought resistance and desiccation tolerance is the accumulation of neutral lipids, foremost triacylglycerol (TAG), in cytosolic lipid droplets (LDs) also referred to as oil bodies, lipid bodies or oleosomes. Several protein families are known to localize to LDs and two of them caleosin (CLO) and lipid droplet associated protein (LDAP) are associated with drought stress responses and possibly evolved this function in streptophyte algae. The goal of the research project is to find out if the accumulation of neutral lipids in LDs is a universal drought stress and desiccation response in the clade of Streptophyta by investigating the five species Mesotaenium endlicherianum, Zygnema circumcarinatum, Physcomitrium patens, Marchantia polymorpha and Azolla filiculoides. Furthermore, we want to collect evidence that LD-associated proteins that are upregulated during drought are important to cope with this stress, and evolved this function already in streptophyte algae. Overall, this data would support the hypothesis that the accumulation of LDs and its associated proteins during drought was one of the prerequisites for the conquer of land. The key objectives are to collect evidence for the following hypotheses: 1. The remodeling of the lipidome and the accumulation of neutral lipids in LDs is a universal stress response. We will monitor the abundance of LDs by microcopy and perform lipidome analyses in drought-treated vegetative tissues of the five species. 2. The proteins CLO and LDAP are universally upregulated under desiccation and drought stress, respectively. We will test the transcript of all respective genes by qPCR in all five species and isolate LDs from drought stressed tissues to analyze these by proteomics. 3. CLO and LDAP are important during drought stress and/or in spores in P. patens. We will knock out the three CLO and the single LDAP gene by CRISPR/Cas9 and analyze the phenotypes in respect to LD number and size, drought resistance and the performance of the spores. 4. CLO and LDAP have kept a similar function throughout evolution from streptophyte algae to land plants. We will complement the P. patens mutant lines that have displayed phenotypes with homolog genes from M. endlicherianum.

干旱是植物在征服土地过程中必须克服的主要胁迫因素。大多数陆地植物都能够在细胞水平上适应干旱。此外，它们能够产生耐干燥的细胞和组织作为其生殖周期的一部分，如种子，花粉和孢子。然而，许多链霉菌藻类也表现出高的应激恢复力。虽然抗旱性很可能独立进化了几次，但这些独立的耐旱性起源也可能受到类似策略和现有适应性监管计划的共同选择的支持。抗旱性和干燥耐受性的共同点是中性脂质（最重要的是三酰甘油（TAG））在细胞溶质脂滴（LD）中的积累，所述脂滴也称为油体、脂质体或油质体。已知几个蛋白质家族定位于LD，其中两个caleosin（CLO）和lipid droplet associated protein（LDAP）与干旱胁迫反应相关，并且可能在链藻中进化出这种功能。该研究项目的目的是通过调查五种物种Mesotaenium endlicherianum，Zygnema circumcarinatum，Physcomitrium patens，Marchantia polymorpha和Azolla filiculoides，来找出LD中中性脂质的积累是否是链霉菌分支中普遍的干旱胁迫和干燥反应。此外，我们希望收集证据表明，在干旱期间上调的LD相关蛋白对于应对这种压力很重要，并且已经在链藻中进化出了这种功能。总体而言，这些数据将支持这样的假设，即在干旱期间LD及其相关蛋白的积累是征服土地的先决条件之一。主要目的是为以下假设收集证据：1。LD中脂质体的重塑和中性脂质的积累是普遍的应激反应。我们将通过显微镜监测LD的丰度，并在干旱处理的五个物种的营养组织中进行脂质组分析。2.蛋白质CLO和LDAP普遍上调干燥和干旱胁迫下，分别。我们将通过qPCR在所有五个物种中测试所有相应基因的转录物，并从干旱胁迫组织中分离LD以通过蛋白质组学分析这些。3. CLO和LDAP在干旱胁迫期间和/或在P.patens的孢子中是重要的。我们将通过CRISPR/Cas9敲除三个CLO和单个LDAP基因，并分析LD数量和大小，抗旱性和孢子性能方面的表型。4. CLO和LDAP在从链藻到陆生植物的进化过程中一直保持着相似的功能。我们将用来自M. patens的同源基因补充表现出表型的P.patens突变株系。endlicherianum。