{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,12]],"date-time":"2026-08-12T05:28:29Z","timestamp":1786512509795,"version":"build-2736575974"},"reference-count":31,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,8,12]],"date-time":"2026-08-12T00:00:00Z","timestamp":1786492800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Plant Sci."],"abstract":"<jats:p>\n                    Plants synthesize diverse isoprenoids that are essential for growth, development, and adaptation to environmental stress. In\n                    <jats:italic>Camellia oleifera<\/jats:italic>\n                    , squalene is a valuable minor constituent of seed oil, yet the regulatory processes linking postharvest stress to squalene accumulation remain poorly understood. Here, we investigated the relationship between protein phosphatase 1-associated responses and changes related to 3-hydroxy-3-methylglutaryl-coenzyme A reductase during postharvest squalene accumulation in\n                    <jats:italic>Camellia oleifera<\/jats:italic>\n                    seeds exposed to 35\u00a0\u00b0C and 95% relative humidity. Squalene content increased rapidly and reached approximately 2.6 times its initial level after 24\u00a0h. By contrast, the enzyme-linked immunosorbent assay-based immunoreactive signal associated with 3-hydroxy-3-methylglutaryl-coenzyme A reductase increased more gradually and remained approximately 30\u201340% above the initial level from 24 to 48\u00a0h. Transcriptome analysis showed that\n                    <jats:italic>CoHMGR2<\/jats:italic>\n                    , the most abundant 3-hydroxy-3-methylglutaryl-coenzyme A reductase transcript at 0 and 12\u00a0h, declined during treatment, whereas several downstream genes in the mevalonate pathway showed treatment-responsive increases. These contrasting patterns indicate that the observed response associated with 3-hydroxy-3-methylglutaryl-coenzyme A reductase could not be explained by transcript abundance alone. Two genes encoding protein phosphatase 1 catalytic subunits also showed increased expression. Recombinant-protein pull-down assays supported an association\n                    <jats:italic>in vitro<\/jats:italic>\n                    between a\n                    <jats:italic>Camellia oleifera<\/jats:italic>\n                    3-hydroxy-3-methylglutaryl-coenzyme A reductase protein and a protein phosphatase 1 catalytic subunit under the defined assay conditions. Metabolomic profiling revealed extensive metabolic reorganization during the major phase of squalene accumulation. Pull-down proteomic analysis further identified candidate proteins associated with 3-hydroxy-3-methylglutaryl-coenzyme A reductase that were functionally annotated to mitochondrial energy metabolism, redox homeostasis, protein folding, and membrane trafficking. Collectively, these findings support a cautious model in which protein phosphatase 1-associated responses are linked to changes related to 3-hydroxy-3-methylglutaryl-coenzyme A reductase and to reorganization of the mevalonate pathway during postharvest squalene accumulation. Whether protein phosphatase 1 directly regulates 3-hydroxy-3-methylglutaryl-coenzyme A reductase through dephosphorylation remains to be determined by targeted biochemical and phosphoproteomic analyses. This study extends the current protein phosphatase 2A-centered framework of plant 3-hydroxy-3-methylglutaryl-coenzyme A reductase regulation and supports protein phosphatase 1 as a candidate component of a regulatory context associated with sterol and triterpene metabolism in a woody oil crop.\n                  <\/jats:p>","DOI":"10.3389\/fpls.2026.1895304","type":"journal-article","created":{"date-parts":[[2026,8,12]],"date-time":"2026-08-12T04:45:51Z","timestamp":1786509951000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["PP1-associated responses linked to HMGR-related changes during postharvest squalene accumulation in Camellia oleifera seeds"],"prefix":"10.3389","volume":"17","author":[{"given":"Jianwen","family":"Wu","sequence":"first","affiliation":[{"name":"Guangxi Forestry Research Institute, Guangxi Laboratory of Forestry","place":["Nanning, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jihua","family":"Guan","sequence":"additional","affiliation":[{"name":"Guangxi Forestry Research Institute, Guangxi Laboratory of Forestry","place":["Nanning, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mi","family":"Qiu","sequence":"additional","affiliation":[{"name":"Guangxi Forestry Research Institute, Guangxi Laboratory of Forestry","place":["Nanning, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wen","family":"Chen","sequence":"additional","affiliation":[{"name":"Guangxi Forestry Research Institute, Guangxi Laboratory of Forestry","place":["Nanning, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Guiqing","family":"Li","sequence":"additional","affiliation":[{"name":"Guangxi Forestry Research Institute, Guangxi Laboratory of Forestry","place":["Nanning, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,8,12]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"133","DOI":"10.1146\/annurev.biophys.27.1.133","article-title":"The structure and mechanism of protein phosphatases: Insights into catalysis and regulation","volume":"27","author":"Barford","year":"1998","journal-title":"Annu. 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