Over-expression of Transcription Factor Increases Yield in Rice

Simultaneously Enhancing Tolerance to Stresses

At a Glance

Researchers at Colorado State University have developed a novel transcription factor that when inserted near a particular gene in rice, causes increased biomass, yield, and stress tolerance (both abiotic and biotic) when compared to the wild-type.  Methods including recombinant expression cassettes, gene-editing, transgenic plant creation and breeding strategy were also developed. Additionally, this could be applicable in other cereals such wheat, maize, barley, and oats.

Background

Crops such as corn, rice, and wheat, account for over half the total human caloric intake.  With global population growth putting significant strain on energy and food securities, a focus has been on increasing harvestable yields of these essential crops.  Traditional methods of improving crop yield have centered on breeding techniques; and while significant improvements have been achieved, breeding techniques are laborious and slow.  Furthermore, for many crops, yield increases have significantly slowed as genetic potential for increases have already been exploited.

Overview

A rice T-DNA insertion mutant causes a mutagenic event that altered the expression and/or function of a nearby gene or genes. Further investigation via RT-PCR supported this claim, as the expression level of one of the neighboring genes is significantly upregulated with the presence of the T-DNA insertion. This particular gene is a transcription factor belonging to a large superfamily of genes in plants. Further phenotypic investigation suggests that the degree of the phenotype (i.e. the increase in biomass) might also be influenced by abiotic and/or biotic stress. Plants placed under drought, pH, and salt stress are more successful in accumulating biomass, and producing seed with the over-expression of this particular transcription factor than wild type controls. This transcription factor appears to have little to no expression in wild-type plants based on preliminary analysis. Creation of AP2 overexpression lines through biotechnology approaches could significantly aid in bioenergy and food security alike. Moreover, the ability for these plants to be more successful in abiotically/biotically stressed environments could increase yields and growth potential for places that are not necessarily ideal for plant growth.

The over-expression pattern and phenotype have correlated 100% across multiple generations, including segregating backcrossing populations.  Mutant rice plants exhibited as high as a 7.4-fold increase in biomass and a simultaneous 3.6-fold increase in seed yield.  These plants also exhibited a delay in flowering time by an average of 16 days. The longer vegetative growth period only partially accounted for the increased biomass; the mutant rice plants also possess longer and wider leaves, and increased tiller girth.

Benefits

  • Increases yield and biomass in rice
  • Provides improved abiotic and biotic stress tolerance
  • Potential to work in other cereal crops as well

Applications

  • Transgenic breeding
  • Gene-editing of cereal crops
  • Plant breeding methods and techniques
Last Updated: January 2024
Rice plant
Opportunity

Available for Licensing
TRL: 3

IP Status

US Patent: US 11,299,523

Inventors

Daniel Bush
Bettina Broeckling
Michael Friedman
Amanda Broz

Reference Number
15-071
Licensing Manager

Jessy McGowan
Jessy.McGowan@colostate.edu
970-491-7100