Root SAT-NAV: uncovering the molecular mechanisms guiding root angle in soil

Root SAT-NAV：揭示土壤中指导根角的分子机制

• 批准号: BB/J009717/1
• 负责人: Malcolm Bennett
• 金额: $ 74.97万
• 依托单位: University of Nottingham
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2012
• 资助国家: 英国
• 起止时间: 2012 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FJ009717%2F1
• 关键词: Root; SAT; NAV; uncovering; molecular

Food security represents a major global issue. Crop production has to double by 2050 to keep pace with global population increasing to 9 billion. This target is even more challenging given the impact of climate change on water availability and the aim to reduce fertilizer inputs to make agriculture become more environmentally sustainable. In both cases, developing crops with improved water and nutrient uptake efficiency would contribute significantly to the solution. Root architecture critically influences nutrient and water uptake efficiency. For example, phosphate uptake efficiency could be significantly improved by manipulating root growth angle to better explore the topsoil where it accumulates. Despite this knowledge, the genes that regulate root angle in crops remain to be identified. Root angle is primarily regulated by the gravitropic response. However, other directional signals like water gradients induce roots' stress-activated-tropisms navigation (SAT-NAV) system when encountering drying soil. Despite their obvious importance, it is currently unclear how hydrotropism interacts with gravitropism to enable roots to forage for water. Understanding the genetic and environmental regulation of root angle is therefore of vital importance to crop improvement.Together with our collaborators, we have recently shown that root tips respond to changes in gravity or moisture by forming gradients of the plant hormones, auxin and ABA, respectively. After a gravity stimulus, auxin accumulates on the lower side of roots, inhibiting cell growth and causing roots to bend in the direction of gravity. We suspect that ABA functions in a similar way to direct root growth towards water. How do these hormones cause these changes? We have identified ~570 genes that auxin regulates to cause root bending. The effect of auxin on root bending is therefore very complicated. To help us deal with this complexity, we will employ a new approach termed Systems Biology that brings together the best of Biology and Maths. This involves generating a large body of experimental information about these different genes and the processes they control that is then integrated into mathematical models. Auxin regulates root bending by inducing responses in many different cells and tissues. Our model therefore has to include information not just about a list of genes but also consider their behaviour in many different root cells and tissues. We then need to determine how realistic our root model is, by designing experiments to test its ability to accurately predict real results. The model can then be used to test ideas and provide new insight about how auxin (or ABA) controls root bending at the gene, cell and tissue level. It will be very important to test whether our findings in the lab are relevant to soil. We will address this important question by exploiting new advances in non-invasive imaging to monitor root growth in soils using X-ray micro Computed Tomography (CT). Using this new imaging capability we will test the impact of altering root gravitropism and hydrotropism on root water and nutrient uptake efficiency in rice. The knowledge gained from this study will help scientists understand how best to manipulate root angle and enhance crop yield.

粮食安全是一个重大的全球问题。到 2050 年，农作物产量必须增加一倍，才能跟上全球人口增长至 90 亿的步伐。考虑到气候变化对水资源供应的影响以及减少化肥投入以使农业变得更加环境可持续的目标，这一目标更具挑战性。在这两种情况下，开发提高水和养分吸收效率的作物将大大有助于解决问题。根系结构严重影响养分和水分的吸收效率。例如，通过控制根部生长角度以更好地探索磷酸盐积累的表土，可以显着提高磷酸盐吸收效率。尽管有了这些知识，调节作物根角的基因仍有待确定。根角主要由向地性响应调节。然而，当遇到干燥的土壤时，其他方向信号（如水梯度）会诱导根部的应激激活向性导航（SAT-NAV）系统。尽管它们的重要性显而易见，但目前尚不清楚向水性与向地性相互作用如何使根部能够觅食水。因此，了解根角的遗传和环境调节对于作物改良至关重要。我们最近与我们的合作者一起证明，根尖通过分别形成植物激素、生长素和 ABA 的梯度来响应重力或湿度的变化。重力刺激后，生长素积聚在根的下侧，抑制细胞生长，导致根向重力方向弯曲。我们怀疑 ABA 的功能与引导根向水方向生长类似。这些激素如何引起这些变化？我们已经鉴定出约 570 个生长素调节导致根部弯曲的基因。因此，生长素对根部弯曲的影响非常复杂。为了帮助我们应对这种复杂性，我们将采用一种称为系统生物学的新方法，它将生物学和数学的精华结合在一起。这涉及生成大量有关这些不同基因及其控制过程的实验信息，然后将其整合到数学模型中。生长素通过诱导许多不同细胞和组织的反应来调节根部弯曲。因此，我们的模型不仅必须包含有关基因列表的信息，还要考虑它们在许多不同根细胞和组织中的行为。然后，我们需要通过设计实验来测试其准确预测真实结果的能力，从而确定我们的根模型的现实程度。然后，该模型可用于测试想法并提供有关生长素（或 ABA）如何在基因、细胞和组织水平上控制根部弯曲的新见解。测试我们在实验室的发现是否与土壤相关非常重要。我们将通过利用 X 射线微型计算机断层扫描 (CT) 监测土壤中根系生长的非侵入性成像的新进展来解决这个重要问题。利用这种新的成像功能，我们将测试改变根部向地性和向水性对水稻根部水分和养分吸收效率的影响。从这项研究中获得的知识将帮助科学家了解如何最好地控制根角并提高作物产量。

项目成果

Effects of rooting media on root growth and morphology of Brassica rapa seedlings

生根介质对白菜幼苗根系生长和形态的影响

• DOI: 10.1080/02571862.2016.1141336
• 发表时间: 2016
• 期刊: South African Journal of Plant and Soil
• 影响因子: 0.9
• 作者: Adu M

Malcolm Bennett.

马尔科姆·贝内特。

• DOI: 10.1016/j.cub.2012.11.033
• 发表时间: 2013
• 期刊: CB
• 作者: Bennett M

The roots of future rice harvests.

• DOI: 10.1186/s12284-014-0029-y
• 发表时间: 2014-12
• 期刊: Rice (New York, N.Y.)
• 作者: Ahmadi N;Audebert A;Bennett MJ;Bishopp A;de Oliveira AC;Courtois B;Diedhiou A;Diévart A;Gantet P;Ghesquière A;Guiderdoni E;Henry A;Inukai Y;Kochian L;Laplaze L;Lucas M;Luu DT;Manneh B;Mo X;Muthurajan R;Périn C;Price A;Robin S;Sentenac H;Sine B;Uga Y;Véry AA;Wissuwa M;Wu P;Xu J
• 通讯作者: Xu J