{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,20]],"date-time":"2026-01-20T02:23:06Z","timestamp":1768875786563,"version":"3.49.0"},"reference-count":41,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2024,8,20]],"date-time":"2024-08-20T00:00:00Z","timestamp":1724112000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Gansu Academy of Agricultural Sciences","award":["2023GAAS11"],"award-info":[{"award-number":["2023GAAS11"]}]},{"name":"Gansu Academy of Agricultural Sciences","award":["32160696"],"award-info":[{"award-number":["32160696"]}]},{"name":"Gansu Academy of Agricultural Sciences","award":["23YFNA0025"],"award-info":[{"award-number":["23YFNA0025"]}]},{"name":"National Natural Science Foundation of China","award":["2023GAAS11"],"award-info":[{"award-number":["2023GAAS11"]}]},{"name":"National Natural Science Foundation of China","award":["32160696"],"award-info":[{"award-number":["32160696"]}]},{"name":"National Natural Science Foundation of China","award":["23YFNA0025"],"award-info":[{"award-number":["23YFNA0025"]}]},{"name":"Gansu Provincial Key R&amp;D Project","award":["2023GAAS11"],"award-info":[{"award-number":["2023GAAS11"]}]},{"name":"Gansu Provincial Key R&amp;D Project","award":["32160696"],"award-info":[{"award-number":["32160696"]}]},{"name":"Gansu Provincial Key R&amp;D Project","award":["23YFNA0025"],"award-info":[{"award-number":["23YFNA0025"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Plants"],"abstract":"<jats:p>The PYL protein family are crucial sensors of the core signals of abscisic acid (ABA) and significantly influence the plant\u2019s response to ABA-mediated abiotic stresses as well as its growth and development. However, research on the role of the MhPYL4 gene in iron (Fe) deficiency in apple trees is limited. Studies have shown that the MhPYL4 gene, when exposed to Fe-deficiency stress, exhibits more rapid transcriptional upregulation than other genes\u2019 quickly elevated transcription. However, the precise mechanism by which it alleviates this stress remains unclear. The MhPYL4 gene (ID:103432868), isolated from Malus halliana, was analyzed to elucidate its function. Arabidopsis plants engineered to overexpress the MhPYL4 gene exhibited increased leaf chlorosis and slower growth in response to Fe stress compared to the unmodified controls. The transgenic plants also exhibited elevated levels of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activities, as well as ferric chelate reductase (FCR) activities. Levels of malondialdehyde (MDA), hydrogen peroxide (H2O2), and superoxide anion (O2\u2212) were increased. In addition, these transgenic plants had lower concentrations of proline (Pro) and Fe2+, which indicated that their stress tolerance was reduced. Similarly, the overexpression of MhPYL4 in apple calli resulted in inhibited growth and increased susceptibility under Fe stress conditions. Physiological evaluations indicated that the overexpression of MhPYL4 in Arabidopsis reduced its Fe stress tolerance by inhibiting chlorophyll synthesis. In apple calli, it altered pH levels, antioxidant enzyme activity, and Fe-reducing capabilities under the same stress conditions. In summary, the elevated expression of the MhPYL4 gene reduced the tolerance of both Arabidopsis and apple calli to Fe stress, suggesting that MhPYL4 acts as a negative regulator in response to Fe deficiency.<\/jats:p>","DOI":"10.3390\/plants13162317","type":"journal-article","created":{"date-parts":[[2024,8,20]],"date-time":"2024-08-20T09:13:48Z","timestamp":1724145228000},"page":"2317","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Functional Identification of MhPYL4 Involved in Iron-Deficiency Stress in Malus Halliana Koehne"],"prefix":"10.3390","volume":"13","author":[{"given":"Xiaoya","family":"Wang","sequence":"first","affiliation":[{"name":"College of Horticulture, Gansu Agricultural University, Lanzhou 730070, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Zhongxing","family":"Zhang","sequence":"additional","affiliation":[{"name":"College of Horticulture, Gansu Agricultural University, Lanzhou 730070, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yongjuan","family":"Dong","sequence":"additional","affiliation":[{"name":"College of Horticulture, Gansu Agricultural University, Lanzhou 730070, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yanxiu","family":"Wang","sequence":"additional","affiliation":[{"name":"College of Horticulture, Gansu Agricultural University, Lanzhou 730070, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2024,8,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"813","DOI":"10.1039\/C7MT00136C","article-title":"Iron homeostasis in plants\u2014A brief overview","volume":"9","author":"Connorton","year":"2017","journal-title":"Metallomics"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"541","DOI":"10.1007\/s00425-002-0920-4","article-title":"Iron uptake, trafficking and homeostasis in plants","volume":"216","author":"Hell","year":"2003","journal-title":"Planta"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"2273","DOI":"10.1016\/j.febslet.2007.04.043","article-title":"Mining iron: Iron uptake and transport in plants","volume":"581","author":"Kim","year":"2007","journal-title":"FEBS Lett."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"3446","DOI":"10.1002\/1873-3468.13257","article-title":"AtROP6 is involved in reactive oxygen species signaling in response to iron-deficiency stress in Arabidopsis thaliana","volume":"592","author":"Zhai","year":"2018","journal-title":"FEBS Lett."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Schmidt, W., Thomine, S., and Buckhout, T.J. 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