The shape of sustainable crop production - re-engineering plant architecture for sustainable food production

可持续作物生产的形态——为可持续粮食生产重新设计植物结构

• 批准号: 2878037
• 金额: --
• 依托单位: University of Leeds
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2878037
• 关键词: shape; sustainable; crop; production; re

This project is focused on better characterising the molecular mechanisms behind gravitropic responses in plant shoots and roots for important crop species. This is for the purpose of engineering crop architecture to improving light capture and decrease lodging occurrence (shoots) and/or nutrient acquisition and drought tolerance (roots).Previous work in this field has established that lateral roots and shoots maintain their growth angles through gravitropic set-point angles as seen in arabidopsis model organisms. The gravitropic-set point angle is the angle defined by its relationship to the gravity vector so a vertically downward shoot/root possessing a GSA of 0 and plant organs are maintained at this GSA in response to gravitropism (Digby, Fern, 1995). This gravity-dependent process is mediated by auxin phytohormones with auxin flux on the upper and lower side leading to differential elongation or elongation inhibition in the shoots and roots respectively. The gravity-sensing apparatus of the root/shoot tip, according to the startch-statolith hypothesis, the columella of dicot and monocot roots and the statocytes of dicot shoots are a collection of polarised cells containing starch-filled amyloplasts which respond to gravity through starch sedimentation to a particular pole of the cell. As a consequence of downward starch sedimentation to the nascent bottom region of the cell when the root/shoot is moved away from the vertical, there is increased downward flux of auxin to the abaxial side of the shoot/root. This acts against the anti-gravitropic offset flux of auxin to the adaxial side of the shoot and root. This disparity between adaxial and abaxial auxin concentrations across the organ leads to differential cell elongation followed by the upward bending in shoots and downwards bending in roots to return to their initial GSAs for optimal plant growth (Roychoudhry and Kepinski 2021).The molecular process behind this gravity-sensing mechanism has been well characterised in arabidopsis models with work. For example, the role of the auxin transporters PIN3, 4 and 7 and their role in establishing gravicompetence in shoots and roots (Roychoudhry et al., 2022). However, translating this understanding of root and shoot responses to gravity and how that impacts plant architecture is still necessary for numerous important crop species, with efforts aimed at improving rooting for increase nutrient/water acquisition in response to increasing drought prevalence under climate change (as well as decreasing shoot lodging where the plant stem snaps whilst maintaining crop yield).Work into cereal species such as wheat and rice has been conducted by fellow postgraduate researchers at the University of Leeds, and elsewhere, with both wheat and rice lateral roots returning to their original GSAs with wheat laterals restoring their GSAs faster than rice laterals which shows variation in the response between species as well as monocots (cereals) and dicots (arabidopsis) with rice potentially possessing a stronger auxin-dependent anti-gravitropic offset response relative to wheat lateral roots. Additionally, rice DRO1 which regulates root growth angle has shown to lead to higher rice yields in water-scarce environments when overexpressed as more vertical root systems are developed (Walsh et al., unpublished). Continuing to elucidate the molecular mechanisms of root and shoot angle development and maintenance in crop species can act as a crucial tool in improving crop yields and establishing better food security. Some crops such as Barley and Sorghum have some early research established whilst other staple crops like soybean have none. This PhD project aims to expand the knowledge of root and shoot angles in these seminal crop species to engineer crops that are resilient to the ever worsening issues of climate change with key emphasis on staple crops like rice and wheat.

该项目的重点是更好地表征重要作物物种的植物芽和根的向地反应背后的分子机制。这是为了改造作物结构，以改善光捕获并减少倒伏发生（芽）和/或养分获取和耐旱性（根）。该领域的先前工作已经确定侧根和芽通过向地性保持其生长角度在拟南芥模型生物体中看到的设定点角度。向地性设定点角度是由其与重力矢量的关系定义的角度，因此具有 GSA 0 的垂直向下的芽/根和植物器官响应向地性而保持在该 GSA（Digby，Fern，1995）。这种重力依赖性过程由生长素植物激素介导，上侧和下侧的生长素通量分别导致芽和根的差异伸长或伸长抑制。根/茎尖的重力感应装置，根据起始-平衡石假说，双子叶植物和单子叶植物根的小柱以及双子叶植物茎的状态细胞是含有淀粉质淀粉体的极化细胞的集合，这些细胞通过淀粉对重力做出反应沉降到细胞的特定极。当根/枝离开垂直方向时，由于淀粉向下沉降到细胞的新生底部区域，所以生长素向枝/根远轴侧的向下通量增加。这对抗生长素向芽和根的近轴侧的反重力偏移通量。整个器官的近轴和远轴生长素浓度之间的差异导致细胞伸长差异，随后芽向上弯曲，根向下弯曲，以返回其初始 GSA 以实现最佳植物生长（Roychoudhry 和 Kepinski 2021）。这背后的分子过程重力感应机制已在拟南芥模型中得到了很好的表征并发挥了作用。例如，生长素转运蛋白 PIN3、4 和 7 的作用及其在芽和根中建立重力能力的作用（Roychoudhry 等人，2022）。然而，对于许多重要的作物物种来说，仍然有必要将这种对根和芽对重力的反应及其如何影响植物结构的理解转化为努力，以改善生根以增加养分/水的获取，以应对气候变化下日益严重的干旱（如利兹大学和其他地方的研究生研究人员对小麦和水稻等谷类物种进行了研究，小麦和水稻的侧根都恢复到了他们最初的 GSA 是小麦侧根恢复其 GSA 的速度比水稻侧根更快，这表明物种以及单子叶植物（谷物）和双子叶植物（拟南芥）之间的响应存在差异，相对于小麦侧根，水稻可能具有更强的生长素依赖性反重力偏移响应。此外，调节根部生长角度的水稻 DRO1 已被证明在缺水环境中过度表达时会导致更高的水稻产量，因为更多的垂直根系会发育出来（Walsh 等人，未发表）。继续阐明作物物种的根和茎角度发育和维持的分子机制可以作为提高作物产量和建立更好的粮食安全的关键工具。大麦和高粱等一些作物已经建立了一些早期研究，而大豆等其他主要作物却没有。该博士项目旨在扩大对这些重要作物物种的根和芽角度的了解，以设计能够抵御日益恶化的气候变化问题的作物，重点关注水稻和小麦等主要作物。