{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,13]],"date-time":"2026-08-13T17:38:51Z","timestamp":1786642731216,"version":"build-2736575974"},"reference-count":34,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2026,8,13]],"date-time":"2026-08-13T00:00:00Z","timestamp":1786579200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100005046","name":"Natural Science Foundation of Heilongjiang Province","doi-asserted-by":"publisher","award":["YQ2022C027"],"award-info":[{"award-number":["YQ2022C027"]}],"id":[{"id":"10.13039\/501100005046","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100005046","name":"Natural Science Foundation of Heilongjiang Province","doi-asserted-by":"publisher","award":["LH2022C053"],"award-info":[{"award-number":["LH2022C053"]}],"id":[{"id":"10.13039\/501100005046","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Harbin University Young Doctor Scientific Research Foundation","award":["HUDF2024205"],"award-info":[{"award-number":["HUDF2024205"]}]},{"award":["HUDF2024205"],"award-info":[{"award-number":["HUDF2024205"]}],"id":[{"id":"https:\/\/ror.org\/00ey9xa07","id-type":"ROR","asserted-by":"publisher"}]},{"name":"Harbin University Special Fund for Rural Revitalization Doctoral Scientific Research","award":["HXC2023003"],"award-info":[{"award-number":["HXC2023003"]}]},{"award":["HXC2023003"],"award-info":[{"award-number":["HXC2023003"]}],"id":[{"id":"https:\/\/ror.org\/00ey9xa07","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Biology"],"abstract":"<jats:p>High temperature can impair leaf water status, photosynthetic function, and membrane stability in ornamental woody seedlings. However, integrated evidence combining gas exchange, chlorophyll fluorescence, oxidative injury, antioxidant activity, and osmotic-adjustment-related responses in heat-stressed Syringa oblata remains limited. One-year-old seedlings from a single nursery batch were exposed for 7 d to 25\/18 \u00b0C or 40\/30 \u00b0C day\/night conditions and sprayed with either a solvent solution or 0.5 mM salicylic acid. Growth, leaf water status, photosynthetic pigments, gas exchange, pulse-amplitude-modulated fluorescence, OJIP\/JIP-test parameters, oxidative-injury markers, antioxidant enzyme activities, and osmotic-adjustment-related compounds were evaluated. Heat treatment reduced leaf relative water content, photosynthetic performance, and photosystem II function and increased reactive oxygen species accumulation, lipid peroxidation, and electrolyte leakage. Compared with heat treatment alone, seedlings receiving salicylic acid under heat showed an 82.2% higher net photosynthetic rate, a 12.2% higher maximum quantum efficiency of photosystem II, and a 116.4% higher performance index on an absorption basis. Hydrogen peroxide, malondialdehyde, and electrolyte leakage were 35.1%, 35.8%, and 32.5% lower, respectively. Antioxidant enzyme activities were also higher under heat plus salicylic acid than under heat alone, whereas additional increases in proline and soluble sugars were not statistically confirmed; soluble protein was partially maintained. Gas exchange was measured after treatment at a common leaf-chamber temperature of 25 \u00b0C and therefore represented retained photosynthetic capacity under standardized conditions. Overall, foliar application of 0.5 mM salicylic acid was associated with partial maintenance of photosynthetic function and lower oxidative injury during short-term heat exposure. Because one chamber was assigned to each treatment combination in a single experimental run, possible chamber-specific effects could not be statistically separated from treatment-related differences. Independent validation is therefore required.<\/jats:p>","DOI":"10.3390\/biology15161389","type":"journal-article","created":{"date-parts":[[2026,8,13]],"date-time":"2026-08-13T17:01:35Z","timestamp":1786640495000},"page":"1389","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Physiological Responses of Syringa oblata Seedlings to Foliar Salicylic Acid Under Short-Term Heat Stress"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3152-8954","authenticated-orcid":false,"given":"Baolong","family":"Du","sequence":"first","affiliation":[{"name":"Heilongjiang Province Key Laboratory of Cold Region Wetland Ecology and Environment Research, School of Geography and Tourism, Harbin University, Harbin 150086, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Weigang","family":"Fu","sequence":"additional","affiliation":[{"name":"Heilongjiang Province Key Laboratory of Cold Region Wetland Ecology and Environment Research, School of Geography and Tourism, Harbin University, Harbin 150086, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0005-6806-9199","authenticated-orcid":false,"given":"Jinbo","family":"Li","sequence":"additional","affiliation":[{"name":"Heilongjiang Academy of Sciences Institute of Natural Resources and Ecology, Harbin 150040, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yuan","family":"Wang","sequence":"additional","affiliation":[{"name":"Heilongjiang Province Key Laboratory of Cold Region Wetland Ecology and Environment Research, School of Geography and Tourism, Harbin University, Harbin 150086, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Juexian","family":"Dong","sequence":"additional","affiliation":[{"name":"Heilongjiang Province Key Laboratory of Cold Region Wetland Ecology and Environment Research, School of Geography and Tourism, Harbin University, Harbin 150086, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jinlong","family":"Li","sequence":"additional","affiliation":[{"name":"Heilongjiang Province Key Laboratory of Cold Region Wetland Ecology and Environment Research, School of Geography and Tourism, Harbin University, Harbin 150086, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nan","family":"Xu","sequence":"additional","affiliation":[{"name":"Heilongjiang Province Key Laboratory of Cold Region Wetland Ecology and Environment Research, School of Geography and Tourism, Harbin University, Harbin 150086, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Haixiu","family":"Zhong","sequence":"additional","affiliation":[{"name":"Heilongjiang Academy of Sciences Institute of Natural Resources and Ecology, Harbin 150040, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,8,13]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Bita, C.E., and Gerats, T. 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