Plant adaptation or acclimation to rising CO2? Insight from first multigenerational RNA-Seq transcriptome

Watson-Lazowski A, Lin Y, Miglietta F, Edwards RJ, Chapman MA & Taylor G (2016): Plant adaptation or acclimation to rising CO₂? Insight from first multigenerational RNA-Seq transcriptome. Glob Chang Biol. Adv. access. doi: 10.1111/gcb.13322

Abstract

Atmospheric carbon dioxide (CO2 ) directly determines the rate of plant photosynthesis and indirectly effects plant productivity and fitness and may therefore act as a selective pressure driving evolution, but evidence to support this contention is sparse. Using Plantago lanceolata L. seed collected from a naturally high CO2 spring and adjacent ambient CO2 control site, we investigated multigenerational response to future, elevated atmospheric CO2 . Plants were grown in either ambient or elevated CO2 (700 μmol mol-1 ), enabling for the first time, characterization of the functional and population genomics of plant acclimation and adaptation to elevated CO2 . This revealed that spring and control plants differed significantly in phenotypic plasticity for traits underpinning fitness including above-ground biomass, leaf size, epidermal cell size and number and stomatal density and index. Gene expression responses to elevated CO2 (acclimation) were modest [33-131 genes differentially expressed (DE)], whilst those between control and spring plants (adaptation) were considerably larger (689-853 DE genes). In contrast, population genomic analysis showed that genetic differentiation between spring and control plants was close to zero, with no fixed differences, suggesting that plants are adapted to their native CO2 environment at the level of gene expression. An unusual phenotype of increased stomatal index in spring but not control plants in elevated CO2 correlated with altered expression of stomatal patterning genes between spring and control plants for three loci (YODA, CDKB1;1 and SCRM2) and between ambient and elevated CO2 for four loci (ER, YODA, MYB88 and BCA1). We propose that the two positive regulators of stomatal number (SCRM2) and CDKB1;1 when upregulated act as key controllers of stomatal adaptation to elevated CO2 . Combined with significant transcriptome reprogramming of photosynthetic and dark respiration and enhanced growth in spring plants, we have identified the potential basis of plant adaptation to high CO2 likely to occur over coming decades.

PMID: 27539677

iOES Poster: Using metagenomics to assess soil microbial diversity under future climate scenarios

Joseph Jenkins, Prof. Gail Taylor, Dr. Rich Edwards.

1st International Environmental Omics Synthesis (iEOS) Conference, Cardiff, UK (Sept 11-13, 2013). Poster CE-3.

Abstract:

Soil microbes are responsible for the function of biogeochemical cycles, which are essential to maintain soil quality. Anthropogenic climate change is resulting in variation of the soil habitat, through alteration of a multitude of soil variables. In particular, prevalence of drought and use of geoengineering methods to sequester carbon (such as biochar) are expected to increase.

To test the implications of drought and biochar amendment in soil habitats, soil samples were collected from two long term experimental sites, and shotgun metagenomic sequencing undertaken to determine changes in soil microbial diversity. Furthermore, analysis of the method itself will be undertaken to determine potential issues with the technique, and to improve the methodology for future studies.

Future work will attempt to compare results of shotgun and amplicon metagenomic methods, and sequencing of additional biochar treated samples from a range of European sites undertaken. This will provide a means to compare changes in microbial diversity after biochar incorporation under a variety of field conditions, providing insight into its likely effects for soil microbial ecology.

iOES Poster: Using Next Generation Sequencing to Understand Plant Acclimation and Adaptation to the Changing Environment

Alex Watson-Lazowski, Yunan Lin, Jennifer DeWoody, Richard Edwards and Gail Taylor.

1st International Environmental Omics Synthesis (iEOS) Conference, Cardiff, UK (Sept 11-13, 2013). Poster EcO-15.

Abstract:

Plant adaptation to elevated atmospheric carbon dioxide (CO2) is of great interest, as the concentration of this gas in the atmosphere has risen by more than 30% to 388 μmol mol-1 since the industrial revolution. On average there has been a rise of 3 ppm per year. Plant fossil samples suggest that atmospheric CO2 may be acting as a selective agent driving evolution, but limited evidence is available to support this idea for plants subjected to future predicted concentrations. Studying evolutionary responses to this aspect of environmental change is difficult, but here we use a CO2 spring site where plants have been exposed for multiple generations to concentrations of CO2 predicted for 2050. From this, detailed phenotyping data was collected, including data for stomatal patterning. Considerable evidence exists to show that stomatal numbers have declined across geological time and that this is linked to CO2 concentration, but few CO2-sensitive stomatal patterning genes have ever been identified. When grown under elevated CO2 concentrations P. lanceolata (the narrow leaf plantain), seeds collected from the spring site showed a counter-intuitive change in stomatal index and density. Here, in this non- model plant we have investigated the gene expression changes underlying this stomatal patterning response to elevated CO2.

RNA-Seq allows for in depth analysis of plant species with no previous information required, enabling rapid evaluation of any of novel plant acclimations and adaptions. Using this approach we have identified a set of novel genes for stomatal patterning in high CO2 and confirmed previously observed acclimation responses.

RNA-Seq refers to the use of high-throughput deep-sequencing technologies to sequence cDNA in order to get information about the transcriptome of a given biological sample.

1st International Environmental Omics Synthesis (iEOS) Conference

The lab has a couple of posters at the 1st International Environmental Omics Synthesis (iEOS) Conference conference in Cardiff this week (Sept 11-13), so come and say hello to Joe and/or Alex if you are in Cardiff.

Poster EcO-15:

UNDERSTANDING PLANT ADAPTATION TO THE CHANGING ENVIRONMENT USING NEXT GENERATION RNA TRANSCRIPTOME SEQUENCING

Alex Watson-Lazowski, Yunan Lin, Jennifer DeWoody, Richard Edwards and Gail Taylor. Centre for Biological Sciences, University of Southampton.

Plant adaptation to elevated atmospheric carbon dioxide (CO2) is of great interest, as the concentration of this gas in the atmosphere has risen by more than 30% to 388 μmol mol-1 since the industrial revolution. On average there has been a rise of 3 ppm per year. Plant fossil samples suggest that atmospheric CO2 may be acting as a selective agent driving evolution, but limited evidence is available to support this idea for plants subjected to future predicted concentrations. Studying evolutionary responses to this aspect of environmental change is difficult, but here we use a CO2 spring site where plants have been exposed for multiple generations to concentrations of CO2 predicted for 2050. From this, detailed phenotyping data was collected, including data for stomatal patterning. Considerable evidence exists to show that stomatal numbers have declined across geological time and that this is linked to CO2 concentration, but few CO2-sensitive stomatal patterning genes have ever been identified. When grown under elevated CO2 concentrations P. lanceolata (the narrow leaf plantain), seeds collected from the spring site showed a counter-intuitive change in stomatal index and density. Here, in this non- model plant we have investigated the gene expression changes underlying this stomatal patterning response to elevated CO2.

RNA-Seq allows for in depth analysis of plant species with no previous information required, enabling rapid evaluation of any of novel plant acclimations and adaptions. Using this approach we have identified a set of novel genes for stomatal patterning in high CO2 and confirmed previously observed acclimation responses.

RNA-Seq refers to the use of high-throughput deep-sequencing technologies to sequence cDNA in order to get information about the transcriptome of a given biological sample.

Poster CE-3:

USING METAGENOMICS TO ASSESS SOIL MICROBIAL DIVERSITY UNDER FUTURE CLIMATE SCENARIOS

Joseph Jenkins, Prof. Gail Taylor, Dr. Rich Edwards. University of Southampton, ExpeER, EuroChar.

Soil microbes are responsible for the function of biogeochemical cycles, which are essential to maintain soil quality. Anthropogenic climate change is resulting in variation of the soil habitat, through alteration of a multitude of soil variables. In particular, prevalence of drought and use of geoengineering methods to sequester carbon (such as biochar) are expected to increase.

To test the implications of drought and biochar amendment in soil habitats, soil samples were collected from two long term experimental sites, and shotgun metagenomic sequencing undertaken to determine changes in soil microbial diversity. Furthermore, analysis of the method itself will be undertaken to determine potential issues with the technique, and to improve the methodology for future studies.

Future work will attempt to compare results of shotgun and amplicon metagenomic methods, and sequencing of additional biochar treated samples from a range of European sites undertaken. This will provide a means to compare changes in microbial diversity after biochar incorporation under a variety of field conditions, providing insight into its likely effects for soil microbial ecology.