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  • 缩略酸酸 - 高级

    Plant morphology buds dormant

    Plant Hormones: Abscisic Acid
    ::植物激素: 缩缩酸

    Abscisic Acid (ABA): Dormancy and Water Conservation
    ::缩水酸(ABA):沉淀和水保护

    Abscisic acid (ABA) governs at least three plant processes – bud dormancy , seed dormancy, and closure of stomata .
    ::减缩酸(ABA)管理至少三个植物过程 — — 胚胎宿舍、种子宿舍和关闭stomata。

    With respect to growth and , ABA is an inhibitory . Its presence stops both development of buds and germination of the embryo . Consider the adaptive value of this kind of inhibition. Many plants living in seasonal environments remain dormant throughout adverse seasons – extended periods of drought, cold, or both. Losing leaves and arresting development conserves energy for the dormant plant. Dormant seeds, produced toward the end of one growing season , must not germinate until the following spring or rainy season, because cold or drought can easily kill most young plants. If winter-dormant plants or seeds relied on temperature to tell them when to resume growth or germinate, they might break dormancy during a January thaw, only to have tender shoots frozen when winter returns. Instead, plants adapted to predictable seasonal climates use declining temperature, daylight, or moisture levels to “set” an internal clock, which could be compared to an egg timer.
    ::在生长和发育方面,ABA是一种抑制。它的存在阻止了胚胎的芽发育和发芽。考虑到这种抑制的适应价值。 许多季节性环境中的植物在整个不利季节 — — 长期干旱、寒冷或两者兼而有之 — — 都处于休眠状态。 脱落和停产为休眠植物节省了能源。 在一个生长季节结束时生产的多曼特种子必须等到下一年春天或雨季才能发芽,因为寒冷或干旱可以轻易杀死大多数年轻的植物。 如果冬冬院植物或种子依靠温度来告诉他们何时恢复生长或发芽,它们可能会在1月的松动期间打破宿舍,只有在冬季返回时,它们才会冷冻的投标。 相反,适应可预见季节性气候的植物会使用温度、日光或湿度下降的“设置”内部时钟,这可以与蛋计时器相比。

    lesson content
    Abscisic acid (ABA) acts somewhat like an egg timer to maintain dormancy in buds (willow). Many plants and seeds in seasonal climates prepare for predictable periods of cold or drought by building up levels of ABA, to inhibit development of buds and embryos. Gradual decline of ABA levels during winter and as water transport begins in spring allows buds to resume growth and seeds to germinate.

    For example, willow and beech are both woody trees. As daylight decreases, these plants produce ABA in leaves and . Leaf and slows, and protective scales, hairs, and/or sticky substances develop to cover the buds. Buds become dormant. Within the seed, the embryo produces ABA, which arrests its development. (In some , seedcoats impermeable to oxygen and contribute to dormancy; these may require a period of cold to allow dormancy to “break”.) For ABA-induced dormancy in buds and embryos, it is only after ABA levels decline – a gradual process throughout the winter, accelerated by the flow of water in spring – that plants or seeds “break dormancy”. Pussy willow “catkins” break out of their buds. Seeds germinate, growing root and shoot, which will develop into a new plant. However, until the time is right, ABA prevents “false starts” during winter thaws.
    ::例如,柳树和树都是木树。随着日落,这些植物在叶叶和叶叶中生产ABA。叶叶和缓慢,以及保护性尺寸、毛发和(或)粘粘物质生长以覆盖芽。 芽开始休眠。 在种子中,胚胎生产ABA,阻止其发育。 (在有些植物中,种子可渗透到氧气中,并助长耐久性。 这可能需要一个寒冷的时期才能允许宿舍“破碎 ” 。 ) 对于ABA在芽和胚胎中引起宿舍的情况,只有在ABA水平下降之后,也就是整个冬季逐渐下降的过程,由于春天的水流加速,植物或种子“断气 ” 。 普西会把“猫头”从芽中解开。 种子发芽、生长根和射击将发展成新的植物。 但是,直到时机成熟之前,ABABA防止冬季的“裂痕”开始。

    In addition to regulating dormancy in buds and seeds, ABA plays a role in a much more rapid response to water shortage. When detect a decline in moisture levels, they produce and release ABA. The hormone travels through the xylem to the leaves, where it affects Na+ and K+ levels in guard cells . Resulting changes in osmotic pressure close the stomata, reducing water loss.
    ::除了调控芽和种子的宿舍外,ABA还发挥作用,对缺水作出更迅速的反应,当发现水分下降时,它们产生并释放ABA。荷尔蒙会穿过xylem到叶子上,影响看守牢房的Na+和K+水平。导致表面压力变化,使斯托马塔关闭,减少缺水。

    The roles played by abscisic acid in seed and bud dormancy and regulation of stomata are supported by several in the model plant Arabidopsis (rock cress). ABA-deficient plants show abnormal stomata function, seed dormancy, and germination.
    ::Arabidopsis(石蜡)示范植物中的若干人支持了腹酸在种子和胚胎宿舍中的作用和对stomata的监管。 ABA缺陷的植物显示出异常的口酸功能、种子宿舍和发芽。

    Summary
    ::摘要

    • Plants produce ABA to inhibit bud development in advance of adverse conditions.
      ::植物生产ABA,在不利条件之前抑制芽发育。
    • ABA in seeds produces similar dormancy; declining levels result in appropriately timed spring germination.
      ::种子的ABA产生相似的宿舍;下降水平导致适当的定时春季发芽。
    • Roots produce ABA in response to decreased availability of water; its transport to leaves closes stomata.
      ::根根生产ABA,以应对水供应的减少;将ABA运到关闭的stomata。