{"id":19629,"date":"2021-05-20T08:16:49","date_gmt":"2021-05-20T08:16:49","guid":{"rendered":"http:\/\/wp.lancs.ac.uk\/sustainable-agriculture\/?p=19629"},"modified":"2021-05-20T08:18:04","modified_gmt":"2021-05-20T08:18:04","slug":"rocket-science-telling-the-story-of-the-c2-enigma","status":"publish","type":"post","link":"http:\/\/wp.lancs.ac.uk\/sustainable-agriculture\/2021\/05\/20\/rocket-science-telling-the-story-of-the-c2-enigma\/","title":{"rendered":"Rocket science: Telling the story of the C2 enigma"},"content":{"rendered":"<p>Written by: Catherine Walsh<\/p>\n<p>Purely by accident, the plan for my PhD research has gained some highly exciting yet potentially controversial hypotheses to test. I am attributing this fresh development to a small extent to the \u2018work from home\u2019 policy adopted by Lancaster University during the pandemic but mainly to my supervisor, Dr Marj Lundgren for giving me the opportunity to work with her on a review paper for the journal, \u2018Biochemical Society Transactions\u2019.<\/p>\n<p>The journal is the publication of the Biochemical Society and represents all aspects of biochemistry across all disciplines. Dr Lundgren was invited to write a review to discuss current knowledge and global research of C<sub>2 <\/sub>photosynthesis with insight into future implications for the mechanism. She invited me to join her on this project as my PhD project investigates the effect of the C<sub>2 <\/sub>mechanism to optimise yield, nutrients and flavour in wild rocket crops. I began by reading intensively (from home), although this time mainly supervised by my cat, Marilyn.<\/p>\n<p>To understand what C<sub>2 <\/sub>photosynthesis is all about, I read an extensive number of papers, on all kinds of biochemical, metabolic and signalling topics. A luxury afforded by the current pandemic situation. Knowledge of the precise biochemistry of the C<sub>2 <\/sub>mechanism is currently limited. It is known to operate in approximately 56 plant species, with rocket being the only commercial crop (Lundgren &amp; Christin 2017). C<sub>2 <\/sub>photosynthesis is essentially a carbon concentrating mechanism, that operates a photorespiratory pump across two cell types to salvage previously lost CO<sub>2 <\/sub>(Sage <em>et al <\/em>2012). The process increases carbon gain under warm, dry conditions without suffering detrimental photorespiratory effects, such as those seen in C<sub>3 <\/sub>species (figure 1).<\/p>\n<p>Previous research states that the C<sub>2 <\/sub>mechanism sits halfway between C<sub>3 <\/sub>and C<sub>4 <\/sub>photosynthesis on an evolutionary trajectory. This is also the case when carbon gain is evaluated under hot environments (Vogan &amp; Sage, 2011). Current thinking now suggests that a functional C<sub>2 <\/sub>pump is a stable state in some cases without further evolutionary pressure (Lundgren, 2020), such as rocket that has no C<sub>4 <\/sub>relatives. Exactly how the C<sub>2 <\/sub>species manage to maintain growth under photorespiratory conditions is a complex question that I have been thinking a lot about.<\/p>\n<p>While working on the review paper, I used rocket as a C<sub>2 <\/sub>example to get my head around what was going on with the biochemistry. Rocket is well known for its health benefits by being a rich source of glucosinolates, vitamins C, K and flavanols. By ticking off these compounds when they cropped up in the literature, I\u2019ve been able to put together some rudimentary ideas for a hypothetical C<sub>2 <\/sub>physiology to suggest how the crop continues to grow in excessive temperatures using highly efficient signalling pathways and integration of carbon, nitrogen and sulphur metabolic pathways. Although, controversially, I am hypothesising that the C<sub>2<\/sub> mechanism is more about generating ammonia in the bundle sheath cell, with CO<sub>2 <\/sub>recycling being incidental.<\/p>\n<p>It has been an interesting journey to co-write a review paper. I\u2019ve learnt a lot about \u00a0plant biochemistry in general, signalling pathways, the C<sub>2 <\/sub>mechanism and how C<sub>2 <\/sub>photosynthesis has a role in the C<sub>4 <\/sub>evolutionary continuum. I also gained experience of the writing process and how the document progressed with each newly gained insight. I am very grateful to Dr Lundgren for giving me the opportunity to work on the paper and to my cat for supervising the excessive reading program. The whole experience has equipped me with some cool hypotheses that I\u2019m looking forward to putting to the test in the lab over the next few months.<\/p>\n<p><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-19630 alignnone\" src=\"https:\/\/i0.wp.com\/wp.lancs.ac.uk\/sustainable-agriculture\/files\/2021\/05\/SchematicRepresentation_CW_20.05.2021.png?resize=300%2C169\" alt=\"\" width=\"300\" height=\"169\" srcset=\"https:\/\/i0.wp.com\/wp.lancs.ac.uk\/sustainable-agriculture\/files\/2021\/05\/SchematicRepresentation_CW_20.05.2021.png?resize=300%2C169 300w, https:\/\/i0.wp.com\/wp.lancs.ac.uk\/sustainable-agriculture\/files\/2021\/05\/SchematicRepresentation_CW_20.05.2021.png?resize=1024%2C576 1024w, https:\/\/i0.wp.com\/wp.lancs.ac.uk\/sustainable-agriculture\/files\/2021\/05\/SchematicRepresentation_CW_20.05.2021.png?resize=768%2C432 768w, https:\/\/i0.wp.com\/wp.lancs.ac.uk\/sustainable-agriculture\/files\/2021\/05\/SchematicRepresentation_CW_20.05.2021.png?w=1333 1333w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/p>\n<p>References:<\/p>\n<p><strong>Lundgren MR, Christin PA. 2017. <\/strong>Despite phylogenetic effects, C<sub>3<\/sub>-C<sub>4 <\/sub>lineages bridge the ecological gap to C<sub>4 <\/sub>photosynthesis. <em>Journal of Experimental Botany <\/em><strong>68<\/strong>: 241-254.<\/p>\n<p><strong>Sage RF, \u00a0Sage TL,\u00a0 Kocacinar F. 2012. <\/strong>Photorespiration and the evolution of C<sub>4 <\/sub>photosynthesis. <em>Annual Review of Plant Biology <\/em><strong>63<\/strong>: 19-47.<\/p>\n<p><strong>Vogan PJ, Sage RF.<\/strong> <strong>2011. <\/strong>Water-use efficiency and nitrogen-use efficiency of C<sub>3<\/sub>-C<sub>4 <\/sub>intermediate species of <em>Flaveria <\/em>Juss. (Asteraceae). <em>Plant, Cell and Environment <\/em><strong>34<\/strong>: 1415-1430.<\/p>\n<p><strong>Lundgren MR. 2020<\/strong>. C<sub>2 <\/sub>photosynthesis: a promising route towards crop improvement? <em>New Phytologist <\/em><strong>228<\/strong>: 1734-1740.<\/p>\n","protected":false},"excerpt":{"rendered":"<p class=\"excerpt\">Written by: Catherine Walsh Purely by accident, the plan for my PhD research has gained some highly exciting yet potentially controversial hypotheses to test. I am attributing this fresh development to a small extent to the \u2018work from home\u2019 policy adopted by Lancaster University during the pandemic but mainly to my supervisor, Dr Marj Lundgren [&hellip;]<\/p>\n","protected":false},"author":1345,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[1],"tags":[],"class_list":["post-19629","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"http:\/\/wp.lancs.ac.uk\/sustainable-agriculture\/wp-json\/wp\/v2\/posts\/19629","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/wp.lancs.ac.uk\/sustainable-agriculture\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/wp.lancs.ac.uk\/sustainable-agriculture\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/wp.lancs.ac.uk\/sustainable-agriculture\/wp-json\/wp\/v2\/users\/1345"}],"replies":[{"embeddable":true,"href":"http:\/\/wp.lancs.ac.uk\/sustainable-agriculture\/wp-json\/wp\/v2\/comments?post=19629"}],"version-history":[{"count":2,"href":"http:\/\/wp.lancs.ac.uk\/sustainable-agriculture\/wp-json\/wp\/v2\/posts\/19629\/revisions"}],"predecessor-version":[{"id":19632,"href":"http:\/\/wp.lancs.ac.uk\/sustainable-agriculture\/wp-json\/wp\/v2\/posts\/19629\/revisions\/19632"}],"wp:attachment":[{"href":"http:\/\/wp.lancs.ac.uk\/sustainable-agriculture\/wp-json\/wp\/v2\/media?parent=19629"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/wp.lancs.ac.uk\/sustainable-agriculture\/wp-json\/wp\/v2\/categories?post=19629"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/wp.lancs.ac.uk\/sustainable-agriculture\/wp-json\/wp\/v2\/tags?post=19629"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}