Dataset Information

Carbon isotope discrimination as a diagnostic tool for C4 photosynthesis in C3-C4 intermediate species.

ABSTRACT: The presence and activity of the C4 cycle in C3-C4 intermediate species have proven difficult to analyze, especially when such activity is low. This study proposes a strategy to detect C4 activity and estimate its contribution to overall photosynthesis in intermediate plants, by using tunable diode laser absorption spectroscopy (TDLAS) coupled to gas exchange systems to simultaneously measure the CO2 responses of CO2 assimilation (A) and carbon isotope discrimination (?) under low O2 partial pressure. Mathematical models of C3-C4 photosynthesis and ? are then fitted concurrently to both responses using the same set of constants. This strategy was applied to the intermediate species Flaveria floridana and F. brownii, and to F. pringlei and F. bidentis as C3 and C4 controls, respectively. Our results support the presence of a functional C4 cycle in F. floridana, that can fix 12-21% of carbon. In F. brownii, 75-100% of carbon is fixed via the C4 cycle, and the contribution of mesophyll Rubisco to overall carbon assimilation increases with CO2 partial pressure in both intermediate plants. Combined gas exchange and ? measurement and modeling is a powerful diagnostic tool for C4 photosynthesis.

SUBMITTER: Alonso-Cantabrana H

PROVIDER: S-EPMC4867892 | biostudies-other | 2016 May

REPOSITORIES: biostudies-other

ACCESS DATA

Publications

Carbon isotope discrimination as a diagnostic tool for C4 photosynthesis in C3-C4 intermediate species.

Alonso-Cantabrana Hugo H von Caemmerer Susanne S

Journal of experimental botany 20160208 10

The presence and activity of the C4 cycle in C3-C4 intermediate species have proven difficult to analyze, especially when such activity is low. This study proposes a strategy to detect C4 activity and estimate its contribution to overall photosynthesis in intermediate plants, by using tunable diode laser absorption spectroscopy (TDLAS) coupled to gas exchange systems to simultaneously measure the CO2 responses of CO2 assimilation (A) and carbon isotope discrimination (Δ) under low O2 partial pre ...[more]

PMID: 26862154

Similar Datasets

Project description:Moricandia arvensis, a plant species originating from the Mediterranean, has been classified as a rare C3-C4 intermediate species, and it is a possible bridge during the evolutionary process from C3 to C4 plant photosynthesis in the family Brassicaceae. Understanding the genomic structure, gene order, and gene content of chloroplasts (cp) of such species can provide a glimpse into the evolution of photosynthesis. In the present study, we obtained a well-annotated cp genome of M. arvensis using long PacBio and short Illumina reads with a de novo assembly strategy. The M. arvensis cp genome was a quadripartite circular molecule with the length of 153,312 bp, including two inverted repeats (IR) regions of 26,196 bp, divided by a small single copy (SSC) region of 17,786 bp and a large single copy (LSC) region of 83,134 bp. We detected 112 unigenes in this genome, comprising 79 protein-coding genes, 29 tRNAs, and four rRNAs. Forty-nine long repeat sequences and 51 simple sequence repeat (SSR) loci of 15 repeat types were identified. The analysis of Ks (synonymous) and Ka (non-synonymous) substitution rates indicated that the genes associated with "subunits of ATP synthase" (atpB), "subunits of NADH-dehydrogenase" (ndhG and ndhE), and "self-replication" (rps12 and rpl16) showed relatively higher Ka/Ks values than those of the other genes. The gene content, gene order, and LSC/IR/SSC boundaries and adjacent genes of the M. arvensis cp genome were highly conserved compared to those in related C3 species. Our phylogenetic analysis demonstrated that M. arvensis was clustered into a subclade with cultivated Brassica species and Raphanus sativus, indicating that M. arvensis was not involved in an independent evolutionary origin event. These results will open the way for further studies on the evolutionary process from C3 to C4 photosynthesis and hopefully provide guidance for utilizing M. arvensis as a resource for improvinng photosynthesis efficiency in cultivated Brassica species.

Dataset Information

Carbon isotope discrimination as a diagnostic tool for C4 photosynthesis in C3-C4 intermediate species.

Publications

Carbon isotope discrimination as a diagnostic tool for C4 photosynthesis in C3-C4 intermediate species.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets