Exploring chemical 'de-priming' and quantitative genetics to improve growth and yield of soybean under abiotic stress.

Lead Research Organisation: University of Glasgow
Department Name: College of Medical, Veterinary &Life Sci

Abstract

One of the first changes in plants exposed to environmental stress is an increase of reactive oxygen species (ROS). During evolution, plants have 'learned' to interpret increased ROS as an early warning signal, and to use it as a trigger to induce physiological and biochemical responses that improve their chances of survival. Plant scientists are trying to understand the molecular components of stress signaling pathways and to exploit this information to develop strategies that can improve the stress tolerance of crops in the field. This is particularly important in India where the agricultural production of nutritious crops such as soybean is limited by environmental and climatic challenges arising from soil salinity, drought, water-logging and/or high temperature.

'Chemical priming' has been proposed as a strategy to enhance the natural stress responses of a plant, for example through pre-treatment with low doses of ROS or ROS-producing agents. Indeed, faster or stronger induction of stress responses and improved plant stress tolerance has been reported for ROS-primed plants. However, our previous research in India has shown that the opposite approach - preventing early stress signaling by applying low concentrations of ROS-scavenging agents such as thiourea (TU) - also improves stress tolerance. The solution to this conundrum is likely to reside in the exact environmental condition ('stress scenario') under which tolerance is tested. To ensure survival, plants tend to prepare for the worst-case scenario. One would therefore expect that enhancing the natural plant responses through priming increases survival under severe long-term stress. However, in an agricultural setting some of the natural responses may be unnecessary and unwanted by the farmer. For example, production of stress-protective metabolites is energetically costly and can delay growth and development of the crop. Furthermore, some responses induced by one stress factor may exacerbate problems generated by another stress factor, e.g. closing stomata saves water under salt/drought stress but disables leaf cooling which is essential for combatting heat stress. Thus, if severe long-term stress does not occur, or is prevented through ad-hoc agricultural measures, crop varieties that ignore early stress signals ('happy-go-lucky' plants) could be better suited to farming in India than stress-sensitive ('panicky') varieties that induce strong stress responses. The aim of scenario-driven strategies would be to narrow the margin between actual and possible yield in a given stress situation.

Following this line of argumentation we propose here a research programme that explores the benefits of both chemical and genetic de-priming for soybean production in Indian agriculture. Based on detailed physiological assays in the laboratory and yield data from field experiments we will establish a dose-effect curve of TU-treatments and determine the specific stress scenarios in which this approach improves soybean performance. The optimised TU formulation can immediately be applied in the field. In the longer term, TU application should be replaced by new custom varieties that are hard-wired to ignore early stress signals. To facilitate the development of 'happy-go-lucky' varieties we will therefore also investigate through RNA-sequencing the molecular processes that are targeted by TU, and carry out a genome-wide association study (GWAS) under single and combined salt/TU treatment. GWAS is possible with soybean because a large panel of accessions with re-sequenced genomes is already available. Correlating phenotypic data (root system architecture, biomass, yield) across these accessions with the genomic data will allow us to identify the genetic loci that underpin TU-modulation of stress responses. The information will enable the development of scenario-based custom varieties with improved stress tolerance through marker-assisted breeding or gene editing technology.

Planned Impact

The primary aim of the proposed research project is to develop a novel stress-desensitizing approach to boost performance of soybean in the field. In India, more than 6.7 million ha arable land is degraded by salinity, which alongside other abiotic stress factors such as drought, water-logging and heat, hampers plant productivity, thus affecting the livelihood of farmers. Increased soybean production under challenging environmental conditions will not only improve the living of farming community but also help in managing hunger and malnutrition in India. The hidden hunger is a serious problem in developing countries, and the prevalence of underweight, stunting and wasting among children is 48, 43 and 20%, respectively, in India. It accounts for 22% of the burden of disease and adversely affects economic growth with an estimated adult productivity loss of 1.4% of GDP. Soybeans derive ~35-38% calories from protein compared to only 20-30% in other legumes. Soy protein was given the top score in an evaluation of protein quality through the Food and Drug Administration (FDA) and the World Health Organization (WHO), equal to that of meat and milk proteins. Soybean is also one of the very few plant sources of omega-3 fat, which is essential for infants and helps to reduce risk of heart disease and cancer in adults. Due to these benefits, soybean has a prominent place among seed legumes, contributing 25% to the global vegetable oil production. Despite being mainly an agricultural country, India pays an import bill of about $15 billion on edible oils. Additionally, owing to soybean contribution towards maintaining soil fertility through nitrogen fixation, the project will positively impact on the overall agriculture growth and consequently the growing Indian economy. Thus, sustainable soybean production can contribute to socio-economic development in India by increasing the production of protein-rich food.

The funding sought here will be an essential step towards this goal. BARC has a research programme characterising the growth-promoting effects of thiourea, a compound that can scavenge reactive oxygen species that are produced by plants during stress. Increased stress tolerance was reported for several crops and proof-of-concept has been obtained for soybean. The proposed collaborative research will precisely define its mode of action (both in the laboratory and in the field) and on this basis develop strategies for farmers and breeders to desensitize plants against stress. Soybean production is predominantly located in the states of Madhya Pradesh and Maharashtra, which contribute to 89% of total production. Hence, we will be targeting these regions to test thiourea efficacy for improving soybean yield and oil quality in salt, heat and drought affected areas.

While carrying out this project, the UK partner will help building research capacity, improving skills and enhancing the knowledge base of the Indian partner group, which will help in uplifting the quality of science in India. Vice-versa the collaboration offers the UK group access to field sites and breeding capacity, and an opportunity to apply their expertise to a project with immediate impact on food security. The proposed work includes many experimental and computational techniques and therefore offers ample opportunity for training of both Indian and UK personnel.

In summary, project success will lead towards (1) enhancement of soybean production, which can promote the economic development and welfare of India, and (2) strengthening of research excellence in India and the UK. Thus, the topic of the proposed project fulfils the remit of the Newton Fund in general and of the 'Pulses and Oilseed' call in particular.
 
Description In the Glasgow lab we have discovered have a role of thiourea in shaping the root architecture of Arabidopsis and in controlling leaf gas exchange though altering kinetics of guard cells. These effects are specific to thiourea (e.g. do not occur with glutathione or additional sulfur). We are now repeating these experiments with two soybean lines.
Field experiments in India have confirmed a positive effect of thiourea application on soybean yield.
Exploitation Route There is a lot of potential for thiourea usage, and we are making progress in understanding its effects on plant physiology and generating exact recommendations for usage in different agricultural scenarios..
Sectors Agriculture, Food and Drink,Education

 
Description Our laboratory experiments have enabled field experiments in India, which have led to engagement with breeders and farmers in India. We have helped the Indian partner with writing scientific articles, editing the English of student authors.
First Year Of Impact 2020
Sector Agriculture, Food and Drink,Education,Environment
Impact Types Cultural,Societal,Policy & public services

 
Description Collaborative project between India and UK: NEWTON BHABHA FUND UK-INDIA PULSES AND OILSEEDS RESEARCH INITIATIVE 
Organisation Bhabbha Atomic Research Centre
Country India 
Sector Public 
PI Contribution We are testing the hypotheses made based on preliminary results from the Indian partners
Collaborator Contribution Provided initial evidence for a positive effect of thiourea on plant stress resistance and carrying out field experiments
Impact Not yet.
Start Year 2018
 
Description Dr. Ashish Srivastava 
Organisation Bhabbha Atomic Research Centre
Country India 
Sector Public 
PI Contribution Dr. Srivastava is our collaborator in India. We provide guidance and training in molecular laboratory techniques and we carry out bioinformatics analysis of RNA-sequencing data.
Collaborator Contribution Dr. Srivastava provides guidance and training on soybean growth and manages the field trials in India.
Impact Dr. Srivastava spent 6 week in our laboratory in Glasgow in May/June 2019. First results have been obtained from the soybean field trials in India.
Start Year 2018
 
Description Editor of a Special Issue on Root Phenotypes for the Future, Plant, Cell & Environment March 2022, with guest-editors Amelia Henry and Malcolm Bennett 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact I initiated, organised and edited a Special Issue on 'Root Phenotypes for the Future with co-editors Amelia Henry, IRRI, and Malcolm Bennett (University of Nottingham). The Special Issue collates 12 review articles and 12 original papers on this important topic of plant science, related to food security and climate change. The Issue received wide interest over Twitter and other social media as well as the journal web page.
Year(s) Of Engagement Activity 2022
URL https://onlinelibrary.wiley.com/toc/13653040/2022/45/3
 
Description Editor-in-Chief of Plant, Cell and Environment 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact Anna Amtmann has taken over as Editor-in-Chief of the International journal Plant Cell and Environment, which is widely read and has an Impact Factor of 6.2.
Year(s) Of Engagement Activity 2018
URL http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1365-3040
 
Description Invited plenary speaker at Rooting 2021 (Joint: 9th International Symposium on Root Development & 11th Symposium of the International Society of Root Research) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact Invited plenary talk in the Session 'Water & Nutrient Relations' at this large joint International conference, including a Q&A session after the talk.
Year(s) Of Engagement Activity 2021
URL https://www.rooting2021.com/
 
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Geographic Reach International
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Results and Impact I regularly share scientific news and topics through my Twitter account (1.5 K followers).
Year(s) Of Engagement Activity 2019,2020,2021,2022
URL https://twitter.com/AnnaAmtmann
 
Description Soeaker at the Festival of Algae2 17-18 Nov 2021 Birmingham organised by BBSRC NIBB Algae UK 
Form Of Engagement Activity A talk or presentation
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Geographic Reach National
Primary Audience Industry/Business
Results and Impact A networking event between academia and Industry aim.ed at enhancing opportunities to grow Industry based on algal products (BBSRC NIBB Algae UK)
Year(s) Of Engagement Activity 2021
URL https://www.algae-uk.org.uk/events/a-festival-of-algae/
 
Description Speaker at COST Conference on Epigenetic Mechanisms of Crop Adaptation To Climate Change 
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Geographic Reach International
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Results and Impact Talk with subsequent discussion at this conference organised by the EU COST action enhancing networking activities in Europe.
Year(s) Of Engagement Activity 2021
URL https://www.epicatch.eu/conference/
 
Description Tutor at Graduate Course: Transcription factors and transcriptional regulation 
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Geographic Reach International
Primary Audience Postgraduate students
Results and Impact I contributed a talk and discussion to this joint post-graduate workshop of The University of Amsterdam and the University of Wageningen (organised by Gerco Angenent (Wageningen University) and Maike Stam (University of Amsterdam)).
Year(s) Of Engagement Activity 2021
 
Description Video Conversation on Plant-Plant Interactions with Dr. Tom Bennett (Leeds), Editor of a Special Issue in Plant, Cell & Environment: 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact In this video two scientists discuss how plants communicate with each other; widely accessed and attracted interest on Social Media (Twitter)
Year(s) Of Engagement Activity 2021
URL https://onlinelibrary.wiley.com/page/journal/13653040/homepage/plant_plant_interactions_conversation