Location: Corn Insects and Crop Genetics Research
2018 Annual Report
Objectives
Objective 1: Develop improved maize phenotyping methods based on process-based crop growth models and high throughput phenotyping methods.
Subobjective 1.1: Develop and validate crop growth model calibrations for diverse maize hybrids to predict maize hybrid performance across diverse environments.
Subobjective 1.2: Evaluate high throughput biochemical and metabolic assays for calibration of crop growth models and prediction of maize grain yield.
Subobjective 1.3: Evaluate remote sensing approaches for improving prediction of maize performance and crop growth model calibration.
Objective 2: Understand the molecular genetic control of gametophytic incompatibility.
Subobjective 2.1: Determine if ZmPme3 complements the ga1 allele to restore the female function of Ga1-s.
Subobjective 2.2: Determine the biochemical mechanism of pollen exclusion by the Ga1 system using E. coli expressed ZmPME3.
Subobjective 2.3: Identify binding partners of ZmPME3.
Approach
In order to used hybrid-specific crop growth models to understand factors contributing to genotype by environment interactions, replicated field trials of hybrid corn varieties will be carried out and evaluated for morphological, phonological and chemical traits. Together with environmental data, these data will be used to develop crop growth models with publicly available software. Valuable measures of agronomic performance such as grain yield of the specific hybrids in the study will be predicted. These models will be validated using actual measurements of agronomic performance and used to predict performance in additional environmental conditions. In order to understand to molecular genetic control mechanism of gametophytic incompatibility, we will construct a transgene encoding ZmPME3 and use it to complement the ga1 phenotype. A second transgene will be used to mutationally inactivate ZmPME3. All transgenic lines will be evaluated for their ability to exclude unwanted pollen in replicated field trials. In addition, ZmPME will be produced in a bacterial expression system and purified. The activity of the purified protein will be characterized using pectin methylesterase activity assays and the effect of this protein on pollen tube growth will be evaluated in vitro.
Progress Report
Data have been assembled for calibrating our first set of crop growth models, which we expect to evaluate soon in crop modeling software. Data collection is in progress for developing and testing models to predict maize grain yield and maize performance (objectives 1.2 and 1.3) by fall. We tested the model we proposed for how ZmPME3 functions to control cross compatibility in three ways.
1. We determined the DNA sequence of ZmPME3 from several maize lines and correlated its presence with the ability to exclude pollen.
2. Initiating work on subobjective 2.2, we began to develop transgenic plants that produce ZmPME3 and a gene editing line that will disrupt the function of ZmPME3.
3. Initiating work on subobjective 2.3, we developed several plasmids to produce ZmPME3 in E. coli.
Accomplishments
