Prevention of Abiotic Stress-Induced Yield Losses in Crops Through Manipulation of Phytohormonal Pathways


Description

The Ozga/Reinecke lab at the University of Alberta has been working with pea as a model crop for 23 years.  The researchers have found that manipulating plant phytohormones (with hormone application or genetic engineering) to increase crop seed yield requires an understanding LicOpp Pic of the mechanisms plants use to set fruit and stimulate seed growth. Based on their work so far, their results indicate that auxins increase pod growth and keep pods growing (Ozga and Reinecke, 2003. J Plant Growth Reg, Ozga et al., 2009. Plant Physiology, Johnstone, Reinecke, Ozga, 2005.
J Plant Growth Reg).

The primary goals of the research have been:

A) Chemical treatments to enhance seed yield under normal and abiotic stress conditions. The main focus for this has been on field pea (Pisum sativum) and wheat (Triticum aestivum), with some work on canola (Brassica napus) and soybean (Glycine max) under controlled environment and field conditions.

B) Transgenic plants with altered gene expression / hormone synthesis & catabolism pathways that lead to enhanced seed yield under normal and abiotic stress conditions. For this work, the focus has been on field pea, with some preliminary experiments conducted on soybean (Glycine max) under controlled environment conditions. In addition, heat stress was used to monitor the crop yield response.

The results for different crop groups follow:

Legume Results:

1. Pea (cv. Carneval)
Under controlled environmental conditions, a single application of 4-Me-IAA prior to or at initial flowering stage increased seed yield per plant by 61-109% under non-heat stress and 20-29% under heat-stress conditions (33-35oC for 6 h per day for 4 days).  A single application of 4-Cl-IAA also increased seed yield by 65% under non-heat stress conditions.
In the field, a single application of 4-Me-IAA increased seed yield per plant by 8 to 43% in 2011 when compared to the control.
Transgenic pea plants with modified transcript levels of the auxin AFB6 receptor were more resistant to heat-stress induced seed yield losses.

2. Soybean (cv. S23-T5)
Under controlled environmental conditions, a single application of 4-Cl-IAA to soybean increased seed yield per plant by 27% under non heat stress conditions when compared to the control.

Wheat Results:

1. (cv. CDC GO; semi-dwarf)
Heat stress (35oC for 6 hours per day for 6 days at the early flowering stage of development) reduced the number of seeds, tillers, and spikes per plant, resulting in lower seed weight per plant compared to the plants which did not receive the heat treatment.
Under controlled environmental conditions, a single application of 4-Cl-IAA at the early flowering stage increased seed weight per plant (20% higher under control greenhouse conditions and 33% higher under the additional heat conditions compare to control). The 4-Cl-IAA-induced increase in seed yield was due to increased number of seeds per plants.  The 4-Cl-IAA treatment did not affect plant height or seed protein content.
In the field, application of 4-Cl-IAA increased the seed yield per plot (8.2% in 2012 and 6% in 2013) compared to the control. The 4-Cl-IAA-induced increase in seed yield per plot was reflected in greater weight per spike in 2012 and 2013, and number of seeds per plant in 2013. The 4-Cl-IAA-induced increase in seed yield per plot did not affect seed protein content or plant height.

Advantages

  • Increased seed yield under normal and abiotic stress.

Protection Status

Two patent families are being pursued for chemical treatments to enhance seed yield under normal and abiotic stress conditions, and for the development of transgenic plants with altered auxin response that lead to enhanced seed yield under normal and abiotic stress conditions.

Patents are issuing.

Product Number

2010064 & 2011003

Contact Information

Darrell Petras
Associate Director – Technology Management Group
TEC Edmonton – University of Alberta
Phone: 780-492-9913
​Email: darrell.petras@www.tecedmonton.com