Identification and functional characterization of HbOsmotin from Hevea brasiliensis.
Identification and functional characterization of HbOsmotin from Hevea brasiliensis.
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DOI：
10.1016/j.plaphy.2016.09.017
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发表时间：
2016-12
期刊：
影响因子：
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通讯作者：
Zheng Tong;Yong Sun;Dan Wang;Limin Wang;Ling Li;Xueru Meng;Weiqiang Feng;E. Wurtele;Xuchu Wang
中科院分区：
文献类型：
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作者：
Zheng Tong;Yong Sun;Dan Wang;Limin Wang;Ling Li;Xueru Meng;Weiqiang Feng;E. Wurtele;Xuchu Wang
橡胶树乳管细胞网络中的胶乳由合成天然橡胶的细胞质组成。乙烯刺激树皮提高胶乳产量的部分原因是延长了割胶过程中胶乳流动的持续时间。在此，我们从巴西血吸虫中鉴定了一个属于病程相关5（PR-5）基因家族的HbOsmotin样cDNA序列。HbOsmotin蛋白存在于巴西海葵的胶乳中，而在洋葱表皮细胞中，该蛋白主要分布在细胞壁周围，这表明它可能是从细胞质中分泌的。本文研究了外源乙烯对拟南芥橡胶胶乳中HbOsmotin转录和蛋白质积累的影响，并进一步确定了渗透胁迫后蛋白质的功能。在定期割胶树，HbOsmotin的表达显着抑制橡胶胶乳割胶后，虽然随后恢复乙烯刺激的表达。而在未割胶的未割胶植株中，外源乙烯处理使HbOsmotin的表达量略有下降，过量表达HbOsmotin表明HbOsmotin降低了植株的渗透胁迫耐受性，这可能是通过提高水势来实现的。这些结果表明，HbOsmotin可能参与乳管细胞的渗透调节。
Latex in the laticiferous cell network of Hevea brasiliensis tree is composed of cytoplasm that synthesizes natural rubber. Ethylene stimulation of the tree bark enhances latex production partly by prolonging the duration of latex flow during the tapping process. Here, we identified an osmotin-like cDNA sequence (HbOsmotin) fromH. brasiliensisthat belongs to the pathogenesis-related 5 (PR-5) gene family. The HbOsmotin protein is present in the lutoids of latex inH. brasiliensis, whereas in onion epidermal cells, this protein is predominantly distributed around the cell wall, suggesting that it may be secreted from the cytoplasm. We investigated the effects of exogenous ethylene onHbOsmotintranscription and protein accumulation in rubber latex, and further determined the protein function after osmotic stress in Arabidopsis. In regularly tapped trees,HbOsmotinexpression was drastically inhibited in rubber latex after tapping, although the expression was subsequently recovered by ethylene stimulation. However, in virgin plants that had never been tapped, exogenous ethylene application slightly decreasedHbOsmotinexpression.HbOsmotinoverexpression inArabidopsisshowed thatHbOsmotinreduced the osmotic stress tolerance of the plant, which likely occurred by raising the water potential. These data indicated thatHbOsmotinmay contribute to osmotic regulation in laticiferous cells.