The betalain secondary metabolic network.

智力优势：甜菜和玫瑰是红色的原因完全不同。几乎所有开花植物都含有两种相互排斥的红色/紫色色素途径中的一种，花青素或甜菜素。花青素生物合成/调控网络已被广泛研究，并存在于绝大多数分类群中，包括主要作物科：禾草科、芸苔科（油菜、芥菜、油菜）和蔷薇科（苹果、梨、樱桃）。另一方面，Betalains仅限于单一目的某些科，即石竹科，它们在所有生物环境中扮演花青素色素的角色。这些作用包括吸引传粉者和种子传播剂，以及在压力和老化过程中作为保护色素。甜菜属植物科包括世界各地种植的农作物和观赏植物，在许多农业经济系统中构成重要的主食，包括甜菜、菠菜、苋菜、藜麦和仙人掌。本项目旨在了解甜菜素在分子水平上的生物合成和调控网络，以及色素紧急特性是如何产生的。花青素来源于氨基酸苯丙氨酸，甜菜素来源于氨基酸酪氨酸。在这个项目开始之前，研究人员发现了一种新的细胞色素P450酶和myb型转录因子调节剂，它们在β蛋白网络中起作用。特别是，将通过沉默甜菜中基因来测试其功能和甜菜基因在酵母中的表达来测试功能，来测试关于最后一个未知甜菜素环结构生物合成酶的身份的假设。一种假设是甜菜素受到与其他植物中调节花青素色素途径相同的一组相互作用蛋白质的调节。研究人员将在甜菜中使用基因沉默和过表达来验证这一假设。花青素受环境信号调控。β素受这些相同信号通路调节的假设将得到验证。为了了解环境信号是否通过增加MYB调节因子的基因表达而起作用，将用已知的激发子和植物激素或营养剥夺（例如磷酸盐）处理植物，并测量所有已知的β蛋白酶网络基因的表达。MYB调节因子直接与β蛋白生物合成基因的顺式区域结合的假设将通过蛋白质- dna结合试验进行验证。更广泛的影响：本研究将增强我们对植物次生代谢网络控制的基本认识。Betalains是重要的膳食抗氧化剂，具有很高的人体可利用性，该项目将导致操纵该网络并将该途径移动到异种系统的能力。最终的影响包括创造对人类和牲畜更有营养的作物的能力。该项目将为各级学生提供优秀的培训。这个项目的组成部分是一个新的以探究为基础的新生研究计划，面向30多名学生，强调科学领域的创造性和批判性思维。学生接受基于讲座的培训，包括假设建立和检验、数据收集、记录保存、统计分析和伦理研究标准。在春季，学生们进入两个学期的实践自我指导的研究流。在过去的十年中，所有实验室成员，包括本科生和研究生，都参加了当地小学年度科学博览会的评审，包括小学生的互动访谈。在过去的六年里，PI和他的研究生们在学校举办了展前拓展研讨会。在过去的一年里，有3名研究生，约180名四五年级学生和6名教师参加了关于假设驱动的科学方法，项目概念和项目执行的研讨会。这项外联活动将在整个项目期间继续进行。

Intellectual merit: Beets and roses are red for completely different reasons. Virtually all flowering plants contain one of two mutually exclusive red/purple pigment pathways, anthocyanins or betalains. The anthocyanin biosynthetic / regulatory network has been heavily studied and occurs in the vast majority of taxa including the major crop families: Poaceae (grasses), Brassicaceae (canola, mustards, cole crops), and Rosaceae (apples, pears, cherries). Betalains on the other hand are restricted to certain families of a single order, the Caryophyllales, where they assume the role of anthocyanin pigments in all biological contexts. These roles include attracting pollinators and seed dispersal agents, and as protective pigments during stress and aging. The betalain families contain crop species and ornamentals that are grown worldwide and form important staples in many agricultural economic systems, including Beets, Spinach, Amaranthus, Quinoa, and Prickly Pear cactus. This project is aimed at understanding the betalain biosynthetic and regulatory network at the molecular level and how pigment emergent properties are generated. While anthocyanins are based on the amino acid phenylalanine, while betalains derive from the animo acid tyrosine. Prior to the start of this project, the investigators identified a novel cytochrome P450 enzyme and a MYB-type transcription factor regulator that function in the betalain network. In particular, hypotheses will be tested regarding the identity of the last unknown betalain ring structure biosynthetic enzyme by silencing genes in beet to test their functions and beet gene expression in yeast to test function. One hypothesis is that betalains are regulated by the same set of interacting proteins that regulate the anthocyanin pigment pathway in other plants. The investigators will test this hypothesis using gene silencing and overexpression in beet. Anthocyanin pigments are regulated by well-characterized environmental signals. The hypothesis that betalains are regulated by these same signaling pathways will be tested. In order to ask the question about whether environmental signals work through increasing gene expression of the MYB regulator, plants will be treated with known elicitors and plant hormones, or nutrient deprivation (e.g. phosphate), and expression of all know betalain network genes will be measured. The hypothesis that the MYB regulator directly binds to cis regions of the betalain biosynthetic genes will be tested through protein-DNA binding assays.Broader impacts: This research will enhance our basic understanding of the control of plant secondary metabolic networks. Betalains are important dietary antioxidants with high human availability and this project will lead to an ability to manipulate this network and to move the pathway into heterologous systems. Eventual impacts include the ability to create crops that are more nutritious for humans and livestock. The project will provide excellent training for all levels of students. Integral to this project is a new inquiry-based Freshman Research Initiative stream for 30+ students that emphasizes creative and critical thinking within science. Students receive lecture-based training in hypothesis building and testing, data collection, record-keeping, statistical analysis, and ethical research standards. In the spring, students enter the stream for two semesters of hands-on self-directed research. For the past ten years, all lab members, including undergrad and grad students, have participated in judging yearly science fairs at local elementary schools, including interactive interviews of the elementary students. For the past six years, the PI and his graduate students have conducted prefair outreach workshops at the schools. This past year, 3 graduate students, about 180 4th and 5th graders, and 6 teachers participated in the workshop on hypothesis driven scientific method, project conception, and project execution. This outreach activity will continue throughout the period of this project.