Wheat development in a changing world

Wheat development in a changing world

Primary Supervisor:

Dr. Laura Dixon (School of Biology, University of Leeds)

Co-supervisor:

Dr. Amanda Bretman (School of Biology, University of Leeds)

Project summary

How do we feed a growing population in a sustainable way during an era of unprecedented climate change? A key component to meeting this challenge is to develop crops which are innately robust against climate change without requiring more chemical inputs to maintain yield. But we can only do this if we have detailed understanding of the interaction between genotypes and environments that drive plant development. For example, wheat accounts for over 40% of the cereal production in the EU but we know relatively little about the daily environmental parameters which regulate its growth. This is because so far the genetic and molecular understanding of plant growth and development has largely been restricted to model plants under controlled conditions or larger seasonal changes. This is most likely due to a lack of tools and resources to study these parameters in crop plants in the field. This has now changed. Using defined germplasm and state-of-the-art technology to capture environmental parameters this project will identify and dissect how the environment is regulating the growth of our primary crop plant Triticum aestivum, bread wheat.

 Project description

Changes in the environment, in particular the new challenges which are occurring through the consequences of climate change, are impacting on final crop yields. Many of the grass crops, including the most widely grown crop in the UK – bread wheat, is particularly sensitive to temperature changes. However, very little is known regarding its growth phases in the field and how different environmental parameters effect these. Knowledge on these will enable us to target particular growth phases for improvement through selective breeding as well as provide information regarding yield prediction through capturing early developmental parameters. This is important in improving the sustainability of farming as accurate early yield predictions could lead to a decrease in field treatments during the growing season.

Conducting detailed analysis of plant growth in the field is essential to identify how climate variables are influence final crop

There are a number of key developmental phases in a wheat plants lifecycle which are regulators of final yield. The first is the transition from vegetative to floral growth, which in winter wheat is controlled by temperature via a process called vernalization [1]. The second is the growth of the tillers (stem elongation) which is controlled through photoperiod signals and finally the timing of the emergence of the wheat flower, duration of flowering and rate of grain filling. Using two sets of defined germplasm which vary for the key photoperiod gene (Ppd-1) or the key vernalization gene (Vrn1) field plots will be grown at the University of Leeds Farm and growth parameters measured through each of the first two growing seasons [2]. In addition, all of the major environmental parameters will be recorded using instrumentation installed at the Farm. This will include; daylength, temperature, soil temperature, precipitation, PAR, soil moisture and through use of a drone we will capture the change in ground cover provided by the crop and the timing of weed competition.

In addition, the same growth parameters on the same sets of germplasm will be measured under controlled glasshouse conditions. Through cross comparison of the data and correlation analysis with the environmental parameters a network will be developed of the key environmental triggers and limiters to wheat growth and how this are influenced by the Ppd and Vrn genes. This is particularly important as these genes are currently the major environmental responders in wheat as either winter, photoperiod sensitive or spring photoperiod insensitive varieties.

 

To further understand wheat plants growth and development circadian (the internal 24 h developmental regulator) analysis will also be conducted across 24 h cycles, firstly under controlled conditions. This will identify if circadian regulators are gating the growth patterns of the wheat plant or if selective breeding has bypassed this. Understanding this again may be important to understand the most effective times of day to apply agricultural chemicals, which would ultimately lead to a reduction in multiple sprays [3].

Expected outcomes

This research will provide detailed insight into how a range of environmental parameters, including and beyond temperature and daylength, are influencing wheat growth and identify the points in the plants development which are most sensitive. This information can be used for a number of applications firstly, selective breeding to develop more robust varieties, secondly for yield predictions and finally to identify targets for selective breeding under alternate climate scenarios. The research will support NERC’s aims of developing more environmentally sustainable agriculture under changing environmental conditions.

Requirements

A strong undergraduate degree in genetics, biology or plant science is expected.  However, training will be provided in all techniques relevant for the project.  If you are not sure if you have the relevant background please feel free to contact the supervisors to discuss the project. In addition a willingness to collect data outside is essential.

Training

This project will provide training in the collection of environmental parameters from a wide range of instrumentation types along with excellent training in plant development and genetics. The field experiments will develop skills in experimental design, multi-parameter analysis and excellent team and individual working skills. The PhD student will have access to a range of training courses designed to facilitate skills development and will be expected to present the outcomes of this project at both national and international conferences.

Research context and partners

Dr Dixon’s research specialises understanding how environmental parameters regulate wheat growth and the interaction of these with the underlying genetic and molecular mechanisms. Her research focuses on identifying the key aspects of the crops biology to provide translation into agriculture to enhance the sustainability of arable farming. Dr Bretman’s research focuses on how organisms respond to environmental stress, including thermal effects on fertility, exploring genetic and epigenetic mechanisms that underpin plastic responses to variable environments [4]. Co-supervisory meetings will happen every 3 months. Through the DTP the student will be embedded into the NERC community at Leeds, and will link with the university-wide Global Food and Environment Institute.

This project will provide an excellent basis for understanding the environmental physiology of crop responses and how this understanding can be used to reduce the number of chemical applications per season. This will have multiple benefits including a reduction in soil compaction and chemical run-off, both of which will increase the sustainability of farming. In more long-term outlook the knowledge from this project will enable the development of more climate robust wheat cultivars at developmental stages previously not considered by wheat breeders.

References

  1. Dixon, Karsai, Kiss, Adamski, Liu, Yang, Allard, Boden, Griffiths (2019) VERNALIZATION1 controls developmental responses of winter wheat under high ambient temperatures Development 146, 3
  2. Shaw, Turner, Laurie. (2012) The impact of photoperiod insensitive ppd-1a mutations on the photoperiod pathway across the three genomes of hexaploid wheat (Triticum aestivum) Plant Journal 71, 71-84
  3. Belbin, Hall, Jackson, Schanschieff, Archibald, Formstone, Dodd (2019) Plant circadian rhythms regulate the effectiveness of a glyphosate-based herbicide Nature Communications 10, 3704
  4. Walsh, Parratt, Hoffmann, Atkinson, Snook, Bretman and Price (2019) The impact of climate change on fertility Trends Eco Evo 34, 249