Polyribosome metabolism, growth and water status in the growing tissues of osmotically stressed plant seedlings
Polyribosome metabolism, growth and water status in the growing tissues of osmotically stressed plant seedlings
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渗透胁迫植物幼苗生长组织中的多核糖体代谢、生长和水分状况
DOI：
10.1111/j.1399-3054.1985.tb01218.x
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发表时间：
1985
影响因子：
6.4
通讯作者：
K. Matsuda
中科院分区：
文献类型：
--
作者：
H. Mason;K. Matsuda
研究了干旱胁迫下完整幼苗生长与多聚核糖体水平和生长组织水分状况之间的关系。大麦（Hordeum vulgare L.）CV. Arivat）根暴露于-0.8 MPa聚乙二醇溶液导致叶片生长几乎立即停止，但在0.5-1 h后以低得多的速率恢复生长。在叶片生长区，胁迫15 min后，游离（非膜结合）核糖体的多聚核糖体与总核糖体的比值显著降低，而大的多聚核糖体与总多聚核糖体的比值仅在胁迫1-2 h后才降低。膜结合和游离的多聚核糖体水平均下降到70%的非应激对照值后4小时的应力。总多聚核糖体的恢复发生在1小时内缓解4小时的压力，但需要3小时后，缓解24小时的压力。胁迫在0.5-1.0 h内显著降低了生长组织的水势和渗透势，渗透调节作用持续至10 h。恢复水分状态是不完全的1小时后，缓解4小时的压力。与此相反，扩大叶片组织的胁迫植物经历了微小的变化，水分状况和多核糖体水平缓慢下降。这些结果证实，大麦叶片的生长组织选择性地响应于胁迫，并表明生长，水分状况和多聚核糖体水平的变化可能是由相同的信号启动。对大、小麦幼苗生长、多聚核糖体水平和生长组织水分状况进行了测定。CV.萨拉戈萨）叶、黄化豌豆（Pisum sativum L.）CV.阿拉斯加）上胚轴和黄化南瓜（Cucurbita pepo L.）CV. Elite）下胚轴用-0.3至-0.8 MPa的聚乙二醇溶液胁迫12小时或更长时间表明，多核糖体水平与幼苗生长速率以及组织水和渗透势高度相关，而膨压保持不变。这些结果表明，长期生长的逆境胁迫植物可能是有限的生长组织中的蛋白质合成能力降低，而不是由膨压损失。
Relationships between growth of osmotically stressed intact seedlings and polyribosome levels and water status of growing tissues were examined. Sudden exposure of barley (Hordeum vulgare L. cv. Arivat) roots to a solution of −0.8 MPa polyethylene glycol caused leaf growth to stop almost immedately, but growth resumed at a much lower rate after 0.5–1 h. In the growing region of leaves, the polyribosome: total ribosome ratio of free (non-membrane-bound) ribosomes was significantly reduced after 15 min stress, but a decrease in the large polyribosome:total polyribosome ratio occurred only after 1–2 h. Membrane-bound and free polyribosome levels both decreased to 70% of unstressed control values after 4 h stress. Recovery of total polyribosomes occurred within 1 h after relief of 4 h stress, but required 3 h after relief of 24 h stress. Stress detectably reduced the water potential and osmotic potential of growing tissue within 0.5–1.0 h, and osmotic adjustment continued for up to 10 h. Recovery of water status was incomplete after 1 h relief of a 4 h stress. In contrast, expanded blade tissues of stressed plants underwent minor changes in water status and slow decreases in polyribosomes levels. These results confirm that growing tissues of barley leaves are selectively responsive to stress, and suggest that changes in growth, water status and polyribosome levels may be initiated by the same signal. Measurements of seedling growth, polyribosome levels and water status of growing tissues of barley and wheat (Triticum aestivum L. cv. Zaragoza) leaves, etiolated pea (Pisum sativum L. cv. Alaska) epicotyl and etiolated squash (Cucurbita pepo L. cv. Elite) hypocotyl stressed with polyethylene glycol solutions of −0.3 to −0.8 MPa for 12 h or more showed that polyribosome levels were highly correlated with seedling growth rate as well as with tissue water and osmotic potentials, while turgor remained unchanged. These results suggest that long-term growth of osmotically stressed plants may be limited by a reduced capacity for protein synthesis in growing tissues and is not dictated by turgor loss.