{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T13:02:41Z","timestamp":1789650161811,"version":"4.0.0"},"reference-count":43,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2026,9,16]],"date-time":"2026-09-16T00:00:00Z","timestamp":1789516800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Special Project on Investigation of Basic Scientific and Technological Resources","award":["2024FY100301-03"],"award-info":[{"award-number":["2024FY100301-03"]}]},{"name":"Modern Seed Industry Development Project","award":["sxzyk202601-7"],"award-info":[{"award-number":["sxzyk202601-7"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Biology"],"abstract":"<jats:p>Photorespiration links carbon metabolism with nitrogen assimilation in C3 plants, but its relationship with nitrogen productivity in perennial turfgrass remains unclear. Ten Kentucky bluegrass (Poa pratensis L.) cultivars were screened for photorespiration rate and intensity. \u2018Heidi\u2019 and \u2018My Holiday\u2019 exhibited the highest and lowest photorespiration intensities (31.17 \u00b1 2.75% and 6.05 \u00b1 1.15%, respectively), and their absolute photorespiration rates were 2.36 \u00b1 0.22 and 0.49 \u00b1 0.09 \u03bcmol CO2\u00b7m\u22122\u00b7s\u22121, representing a 4.8-fold difference. Under baseline conditions, \u2018Heidi\u2019 showed higher NDVI, shoot N concentration, and N accumulation, as well as component-specific differences in selected epidermal traits and biochemical measurements, whereas the measured gas-exchange variables were unchanged. Nitrogen treatments further showed that cultivar responses depended on nitrogen form and application rate. Under low nitrate supply, \u2018My Holiday\u2019 had a higher photorespiration rate than \u2018Heidi\u2019, whereas their partial factor productivity of applied nitrogen based on shoot dry matter (PFPN) did not differ significantly. Comparative transcriptomic analysis identified serine hydroxymethyltransferase 4 (SHM4, hereafter PpSHMT) as a photorespiration-related candidate transcript, with a log2 fold change of 3.37 in \u2018Heidi\u2019 relative to \u2018My Holiday\u2019. qRT-PCR confirmed higher PpSHMT transcript abundance in \u2018Heidi\u2019, but bulk-leaf SHMT relative protein abundance did not differ significantly between the cultivars. Transient delivery of pBI121-PpSHMT into Nicotiana tabacum L. cv. K326 leaves was associated with changes in selected biochemical measurements. Overall, the results demonstrate a treatment-dependent association between photorespiration and nitrogen productivity and identify PpSHMT as a candidate requiring further functional investigation.<\/jats:p>","DOI":"10.3390\/biology15181628","type":"journal-article","created":{"date-parts":[[2026,9,16]],"date-time":"2026-09-16T07:58:59Z","timestamp":1789545539000},"page":"1628","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Photorespiration Is Associated with Nitrogen Metabolism and Nitrogen Productivity in Kentucky Bluegrass"],"prefix":"10.3390","volume":"15","author":[{"given":"Xiaoyan","family":"Li","sequence":"first","affiliation":[{"name":"College of Grassland Science, Shanxi Agriculture University, Taigu, Jinzhong 030801, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2853-2925","authenticated-orcid":false,"given":"Huisen","family":"Zhu","sequence":"additional","affiliation":[{"name":"College of Grassland Science, Shanxi Agriculture University, Taigu, Jinzhong 030801, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"funding-acquisition","vocabulary":"credit"}]},{"given":"Dina","family":"Li","sequence":"additional","affiliation":[{"name":"College of Grassland Science, Shanxi Agriculture University, Taigu, Jinzhong 030801, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"methodology","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"}]},{"given":"Tao","family":"Xu","sequence":"additional","affiliation":[{"name":"College of Grassland Science, Shanxi Agriculture University, Taigu, Jinzhong 030801, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"methodology","vocabulary":"credit"}]},{"given":"Huifang","family":"Cen","sequence":"additional","affiliation":[{"name":"College of Grassland Science, Shanxi Agriculture University, Taigu, Jinzhong 030801, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"funding-acquisition","vocabulary":"credit"}]},{"given":"Yan","family":"Zhang","sequence":"additional","affiliation":[{"name":"College of Grassland Science, Shanxi Agriculture University, Taigu, Jinzhong 030801, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"funding-acquisition","vocabulary":"credit"}]}],"member":"1968","published-online":{"date-parts":[[2026,9,16]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"e70180","DOI":"10.1002\/csc2.70180","article-title":"Kentucky bluegrass characteristics: Germination and establishment speed, rhizomes, and sod production","volume":"65","author":"Nwachukwu","year":"2025","journal-title":"Crop Sci."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"182","DOI":"10.14719\/pst.2020.7.2.637","article-title":"Nitrate assimilation pathway in higher plants: Critical role in nitrogen signalling and utilization","volume":"7","author":"Ali","year":"2020","journal-title":"Plant Sci. Today."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"116372","DOI":"10.1016\/j.envpol.2020.116372","article-title":"Global greenhouse vegetable production systems are hotspots of soil N2O emissions and nitrogen leaching: A meta-analysis","volume":"272","author":"Qasim","year":"2021","journal-title":"Environ. Pollut."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"78","DOI":"10.1111\/gfs.12637","article-title":"Parameters of nitrogen use efficiency of Kentucky bluegrass cultivars at different N levels under deficit irrigation","volume":"79","author":"Zhu","year":"2024","journal-title":"Grass Forage Sci."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"30451","DOI":"10.1073\/pnas.2018939117","article-title":"Biophysical analysis of the structural evolution of substrate specificity in RuBisCO","volume":"117","author":"Poudel","year":"2020","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"3955","DOI":"10.1093\/jxb\/eraa183","article-title":"Photorespiration\u2014How is it regulated and how does it regulate overall plant metabolism?","volume":"71","author":"Timm","year":"2020","journal-title":"J. Exp. Bot."},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Kuhnert, F., Schl\u00fcter, U., Linka, N., and Eisenhut, M. (2021). Transport proteins enabling plant photorespiratory metabolism. Plants, 10.","DOI":"10.3390\/plants10050880"},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Ren, L.C., Pan, X.D., Deng, Y., Ge, Z.K., Li, S.Y., Su, D., Zhao, G.Q., Tang, H., and Wang, X.F. (2024). Combined transcriptomic and metabolomic analyses reveal the mechanisms by which the interaction between sulfur and nitrogen affects garlic yield and quality. Horticulturae, 10.","DOI":"10.3390\/horticulturae10111203"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Shi, X., and Bloom, A. (2021). Photorespiration: The futile cycle?. Plants, 10.","DOI":"10.3390\/plants10050908"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1877","DOI":"10.1038\/s41477-025-02091-w","article-title":"Metabolic flux analysis in leaf metabolism quantifies the link between photorespiration and one carbon metabolism","volume":"11","author":"Gashu","year":"2025","journal-title":"Nat. Plants"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"404","DOI":"10.1093\/plcell\/koad256","article-title":"The serine\u2013glycine\u2013one-carbon metabolic network orchestrates changes in nitrogen and sulfur metabolism and shapes plant development","volume":"36","author":"Saeheng","year":"2024","journal-title":"Plant Cell"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"6023","DOI":"10.1093\/jxb\/erad291","article-title":"Photorespiration: Regulation and new insights on the potential role of persulfidation","volume":"74","author":"Aroca","year":"2023","journal-title":"J. Exp. Bot."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"946","DOI":"10.1111\/tpj.15712","article-title":"A revised view on the evolution of glutamine synthetase isoenzymes in plants","volume":"110","author":"Ortigosa","year":"2022","journal-title":"Plant J."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"330","DOI":"10.1016\/j.tplants.2010.03.006","article-title":"Photorespiration: Players, partners and origin","volume":"15","author":"Bauwe","year":"2010","journal-title":"Trends Plant Sci."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"e12943","DOI":"10.7717\/peerj.12943","article-title":"Genome-wide identification and expression analysis of serine hydroxymethyltransferase (SHMT) gene family in tomato (Solanum lycopersicum)","volume":"10","author":"Liu","year":"2022","journal-title":"PeerJ"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1487","DOI":"10.1093\/plphys\/kiab167","article-title":"The phosphorylated pathway of serine biosynthesis links plant growth with nitrogen metabolism","volume":"186","author":"Zimmermann","year":"2021","journal-title":"Plant Physiol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"163","DOI":"10.2480\/agrmet.66.3.2","article-title":"Photosynthesis and respiration of managed C3 turfgrass fields under various light conditions","volume":"66","author":"Kosugi","year":"2010","journal-title":"J. Agric. Meteorol."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Sun, X., Guo, Z., Jiang, Y., Qin, L., Shi, Z., Dong, L., Xiong, L., Yuan, R., Deng, W., and Wu, H. (2022). Differential metabolomic responses of Kentucky bluegrass cultivars to low nitrogen stress. Front. Plant Sci., 12.","DOI":"10.3389\/fpls.2021.808772"},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Yang, W., Sigrimis, N., Li, M.Z., Sun, H., and Zheng, L.H. (2012). Correlations between nitrogen content and multispectral image of greenhouse cucumber grown in different nitrogen level. International Conference on Computer and Computing Technologies in Agriculture, Springer.","DOI":"10.1007\/978-3-642-36137-1_53"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Kizilgeci, F., Yildirim, M., Islam, M.S., Ratnasekera, D., Iqbal, M.A., and EL Sabagh, A. (2021). Normalized difference vegetation index and chlorophyll content for precision nitrogen management in durum wheat cultivars under semi-arid conditions. Sustainability, 13.","DOI":"10.3390\/su13073725"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"745","DOI":"10.1111\/jipb.12336","article-title":"Characterization and molecular cloning of a serine hydroxymethyltransferase 1 (OsSHM1) in rice","volume":"57","author":"Wang","year":"2015","journal-title":"J. Integr. Plant Biol."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"koaf015","DOI":"10.1093\/plcell\/koaf015","article-title":"Synthetic photorespiratory bypass improves rice productivity by enhancing photosynthesis and nitrogen uptake","volume":"37","author":"Chen","year":"2025","journal-title":"Plant Cell"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"377","DOI":"10.1023\/A:1015178209845","article-title":"Estimation of photorespiration rate by simultaneous measurements of CO2, gas exchange rate, and chlorophyll fluorescence quenching in the C3 plant Vigna radiata (L.) Wilczek and the C4 plant Amaranthus mongostanus L.","volume":"39","author":"Yoshimura","year":"2001","journal-title":"Photosynthetica"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"37","DOI":"10.1007\/s11738-004-0042-7","article-title":"Light-enhanced dark respiration in leaves and mesophyll protoplasts of pea in relation to photorespiration, respiration and some metabolites content","volume":"26","author":"Parys","year":"2004","journal-title":"Acta Physiol. Plant."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"42","DOI":"10.26480\/gwk.01.2021.42.44","article-title":"Leaf anatomy and micromorphology of selected euphorbiaceae species in Kuantan, Pahang, Malaysia","volume":"5","author":"Amri","year":"2021","journal-title":"Eng. Herit. J. (GWK)"},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Yuan, J., Wang, X., Zhou, H., Li, Y., Zhang, J., Yu, S., Wang, M., Hao, M., Zhao, Q., and Liu, L. (2020). Comparison of Sample Preparation Techniques for Inspection of Leaf Epidermises Using Light Microscopy and Scanning Electronic Microscopy. Front. Plant Sci., 11.","DOI":"10.3389\/fpls.2020.00133"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"128201","DOI":"10.1016\/j.foodchem.2020.128201","article-title":"Effect of growing conditions on proximate, mineral, amino acid, phenolic composition and antioxidant properties of wheatgrass from different wheat (Triticum aestivum L.) varieties","volume":"341","author":"Kaur","year":"2021","journal-title":"Food Chem."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"9931763","DOI":"10.1155\/2021\/9931763","article-title":"Growth, Nitrogen Uptake of Maize (Zea mays L.) and Soil Chemical Properties, and Responses to Compost and Nitrogen Rates and Their Mixture on Different Textured Soils: Pot Experiment","volume":"2021","author":"Nigussie","year":"2021","journal-title":"Appl. Environ. Soil Sci."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Congreves, K.A., Otchere, O., Ferland, D., Farzadfar, S., Williams, S., and Arcand, M.M. (2021). Nitrogen Use Efficiency Definitions of Today and Tomorrow. Front. Plant Sci., 12.","DOI":"10.3389\/fpls.2021.637108"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"231","DOI":"10.1146\/annurev-phyto-082718-100101","article-title":"Pathways of DNA Transfer to Plants from Agrobacterium tumefaciens and Related Bacterial Species","volume":"57","author":"Lacroix","year":"2019","journal-title":"Annu. Rev. Phytopathol."},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Senthilkumar, M., Amaresan, N., and Sankaranarayanan, A. (2021). Plant-Microbe Interactions: Laboratory Techniques. Plant-Microbe Interactions, Springer.","DOI":"10.1007\/978-1-0716-1080-0"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"2013","DOI":"10.1104\/pp.108.130153","article-title":"Carbon isotope fractionation during photorespiration and carboxylation in Senecio","volume":"148","author":"Lanigan","year":"2008","journal-title":"Plant Physiol."},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Huang, W., Zheng, Z., Hua, D., Chen, X., Zhang, J., Chen, H., Ye, X., Guo, J., Yang, L., and Chen, L. (2022). Adaptive responses of carbon and nitrogen metabolisms to nitrogen-deficiency in Citrus sinensis seedlings. BMC Plant Biol., 22.","DOI":"10.1186\/s12870-022-03759-7"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"6629","DOI":"10.1038\/s41467-023-42136-2","article-title":"Relationships of stomatal morphology to the environment across plant communities","volume":"14","author":"Liu","year":"2023","journal-title":"Nat. Commun."},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Chen, J., Gao, J., Wang, Q., Tan, X., Li, S., Chen, P., Yong, T., Wang, X., Wu, Y., and Yang, F. (2023). Blue-Light-Dependent Stomatal Density and Specific Leaf Weight Coordinate to Promote Gas Exchange of Soybean Leaves. Agriculture, 13.","DOI":"10.3390\/agriculture13010119"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"uhad075","DOI":"10.1093\/hr\/uhad075","article-title":"Drought stress triggers alterations of adaxial and abaxial stomatal development in basil leaves increasing water-use efficiency","volume":"10","author":"Driesen","year":"2023","journal-title":"Hortic. Res."},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Perdomo, J.A., Cap\u00f3-Bau\u00e7\u00e0, S., Carmo-Silva, E., and Galm\u00e9s, J. (2017). Rubisco and Rubisco Activase Play an Important Role in the Biochemical Limitations of Photosynthesis in Rice, Wheat, and Maize under High Temperature and Water Deficit. Front. Plant Sci., 8.","DOI":"10.3389\/fpls.2017.00490"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"96","DOI":"10.1016\/j.molp.2022.11.015","article-title":"Understanding source\u2013sink interactions: Progress in model plants and translational research to crops","volume":"16","author":"Yokoyama","year":"2023","journal-title":"Mol. Plant"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"26340","DOI":"10.1038\/s41598-024-77049-7","article-title":"Rubisco activity and activation state dictate photorespiratory plasticity in Betula papyrifera acclimated to future climate conditions","volume":"14","author":"Gregory","year":"2024","journal-title":"Sci. Rep."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"13528","DOI":"10.1016\/S0021-9258(18)42243-0","article-title":"Identification and localization of multiple forms of serine hydroxymethyltransferase in pea (Pisum sativum) and characterization of a cDNA encoding a mitochondrial isoform","volume":"267","author":"Turner","year":"1992","journal-title":"J. Biol. Chem."},{"key":"ref_41","doi-asserted-by":"crossref","unstructured":"Gao, R., Chen, L., Chen, F., and Ma, H. (2024). Genome-wide identification of SHMT family genes in alfalfa (Medicago sativa) and its functional analyses under various abiotic stresses. BMC Genom., 25.","DOI":"10.1186\/s12864-024-10637-z"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"305","DOI":"10.1007\/s13205-022-03378-x","article-title":"Genome-wide identification of SHMT family genes in cucumber (Cucumis sativus L.) and functional analyses of CsSHMTs in response to hormones and abiotic stresses","volume":"12","author":"Gao","year":"2022","journal-title":"3 Biotech"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"451","DOI":"10.1111\/j.1365-313X.2004.02311.x","article-title":"Arabidopsis SHMT1, a serine hydroxymethyltransferase that functions in the photorespiratory pathway influences resistance to biotic and abiotic stress","volume":"41","author":"Moreno","year":"2005","journal-title":"Plant J."}],"container-title":["Biology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2079-7737\/15\/18\/1628\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T12:12:47Z","timestamp":1789647167000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2079-7737\/15\/18\/1628"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,16]]},"references-count":43,"journal-issue":{"issue":"18","published-online":{"date-parts":[[2026,9]]}},"alternative-id":["biology15181628"],"URL":"https:\/\/doi.org\/10.3390\/biology15181628","relation":{},"ISSN":["2079-7737"],"issn-type":[{"value":"2079-7737","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,16]]}}}