[{"das_tickbox":"1","title":"Regulation of shoot gravitropism and branching angle by the GRV2-SAC1 axis in Arabidopsis","keyword":["auxin","SAC1","GRV2","PIN3","vacuole","gravitropism","Arabidopsis"],"date_updated":"2026-07-20T13:53:44Z","issue":"1","date_published":"2026-07-01T00:00:00Z","author":[{"full_name":"Sun, Lianghanxiao","first_name":"Lianghanxiao","last_name":"Sun"},{"first_name":"Wenxin","last_name":"Jia","full_name":"Jia, Wenxin"},{"full_name":"Mao, Yanbo","last_name":"Mao","first_name":"Yanbo"},{"full_name":"Li, Xin","last_name":"Li","first_name":"Xin"},{"full_name":"Kong, Mengjuan","first_name":"Mengjuan","last_name":"Kong"},{"full_name":"She, Ji","last_name":"She","first_name":"Ji"},{"full_name":"Friml, Jiří","orcid":"0000-0002-8302-7596","last_name":"Friml","first_name":"Jiří","id":"4159519E-F248-11E8-B48F-1D18A9856A87"},{"full_name":"Tan, Shutang","first_name":"Shutang","id":"2DE75584-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0002-0471-8285","last_name":"Tan"}],"supplementarymaterial":"yes","department":[{"_id":"JiFr"}],"researchdata_availability":"upon request","article_processing_charge":"No","external_id":{"pmid":["42438075"]},"abstract":[{"lang":"eng","text":"Gravitropism is a fundamental adaptive response in plants that enables directional growth to optimize resource acquisition. In this study, we employed forward genetic screening to identify Arabidopsis mutants with defective hypocotyl gravitropism and isolated the short and agravitropic hypocotyl in dark1 (sad1) mutant, which carries a point mutation (G110E) in the SAC1 gene encoding a phosphoinositide phosphatase. Deficiency of SAC1 disrupted gravity-induced polar localization of PIN3 in endodermal cells, impairing auxin redistribution and leading to hypocotyl gravitropism defects. Subcellular localization analysis revealed that SAC1 is partially localized to the PVC/tonoplast and participates in late endosomal trafficking. The sac1 mutation leads to abnormal vacuolar morphology, which is associated with defects in amyloplast sedimentation during the gravitropic response in Arabidopsis shoots. We further revealed that SAC1 interacts with GRV2, a key regulator of the late endocytic pathway, and that both proteins cooperatively regulate shoot gravitropism. In summary, this study identified SAC1 as a regulator of shoot gravitropism, revealing its important role in modulating vacuolar homeostasis, amyloplast sedimentation, PIN3 trafficking, and auxin distribution. These findings provide insights into the molecular mechanisms linking membrane transport to environmental adaptation in plants."}],"publisher":"Wiley","year":"2026","month":"07","dataavailabilitystatement":"Biological materials (seeds, plasmids) are available upon request from ST (sttan@ustc.edu.cn). The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.","language":[{"iso":"eng"}],"status":"public","publication":"The Plant Journal","oa_version":"None","type":"journal_article","date_created":"2026-07-19T22:01:47Z","pmid":1,"scopus_import":"1","acknowledgement":"We acknowledge Prof. Dolf Weijers (Wageningen University), Prof.Karin Schumacher (Heidelberg University), Prof. Yohann Boutt ´e(Universit ´e de Bordeaux), and Prof. Jinbo Shen (Zhejiang A&FUniversity) for providing published plasmids and Arabidopsislines. We thank Dr. Gergely Moln ´ar (ISTA) for help with NGS dataanalysis, and Prof. Jianru Zuo (IGDB, CAS), Prof. Chengbin Xiang(USTC), and Prof. Zhong Zhao (USTC) for critical comments onthe manuscript. We thank the staff members of the Mass Spec-trometry System at the National Facility for Protein Science inShanghai (NFPS), Zhangjiang Lab, China for providing technicalsupport and assistance in data collection and analysis. This workwas supported by grants from the National Natural Science Foun-dation of China (32570366, and 32321001 to ST), the Natural Sci-ence Foundation of Anhui Province (2508085QC070 to MK), theFundamental Research Funds for the Central Universities(WK9100250095 to MK, and WK9100000021 to ST), the ForestryBureau of Anhui Province (AHLYJBGS-2024-01 to ST), the Centerfor Advanced Interdisciplinary Science and Biomedicine of IHM,Division of Life Sciences and Medicine, University of Science andTechnology of China (QYPY20220012 to ST), the USTC ResearchFunds of the Double First-Class Initiative (YD9100002016 to ST),and start-up funding from the University of Science and Technol-ogy of China and the Chinese Academy of Sciences(GG9100007007, KY9100000026, KY9100000051, XKTS-202591014,XKTS-2026910122, and KJ2070000079 to ST).","OA_type":"closed access","publication_status":"published","day":"01","intvolume":"       127","_id":"22366","publication_identifier":{"eissn":["1365-313X"],"issn":["0960-7412"]},"citation":{"mla":"Sun, Lianghanxiao, et al. “Regulation of Shoot Gravitropism and Branching Angle by the GRV2-SAC1 Axis in Arabidopsis.” <i>The Plant Journal</i>, vol. 127, no. 1, e71042, Wiley, 2026, doi:<a href=\"https://doi.org/10.1111/tpj.71042\">10.1111/tpj.71042</a>.","ama":"Sun L, Jia W, Mao Y, et al. Regulation of shoot gravitropism and branching angle by the GRV2-SAC1 axis in Arabidopsis. <i>The Plant Journal</i>. 2026;127(1). doi:<a href=\"https://doi.org/10.1111/tpj.71042\">10.1111/tpj.71042</a>","short":"L. Sun, W. Jia, Y. Mao, X. Li, M. Kong, J. She, J. Friml, S. Tan, The Plant Journal 127 (2026).","apa":"Sun, L., Jia, W., Mao, Y., Li, X., Kong, M., She, J., … Tan, S. (2026). Regulation of shoot gravitropism and branching angle by the GRV2-SAC1 axis in Arabidopsis. <i>The Plant Journal</i>. Wiley. <a href=\"https://doi.org/10.1111/tpj.71042\">https://doi.org/10.1111/tpj.71042</a>","ista":"Sun L, Jia W, Mao Y, Li X, Kong M, She J, Friml J, Tan S. 2026. Regulation of shoot gravitropism and branching angle by the GRV2-SAC1 axis in Arabidopsis. The Plant Journal. 127(1), e71042.","chicago":"Sun, Lianghanxiao, Wenxin Jia, Yanbo Mao, Xin Li, Mengjuan Kong, Ji She, Jiří Friml, and Shutang Tan. “Regulation of Shoot Gravitropism and Branching Angle by the GRV2-SAC1 Axis in Arabidopsis.” <i>The Plant Journal</i>. Wiley, 2026. <a href=\"https://doi.org/10.1111/tpj.71042\">https://doi.org/10.1111/tpj.71042</a>.","ieee":"L. Sun <i>et al.</i>, “Regulation of shoot gravitropism and branching angle by the GRV2-SAC1 axis in Arabidopsis,” <i>The Plant Journal</i>, vol. 127, no. 1. Wiley, 2026."},"volume":127,"article_type":"original","article_number":"e71042","doi":"10.1111/tpj.71042","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","quality_controlled":"1"}]