Growth and lignification in seedlings exposed to eight days of microgravity.
Growth and lignification in seedlings exposed to eight days of microgravity.
复制标题
暴露于八天微重力下的幼苗的生长和木质化。
DOI：
10.1093/oxfordjournals.aob.a086865
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发表时间：
1984
期刊：
影响因子：
4.2
通讯作者：
C. Peterson
中科院分区：
文献类型：
--
作者：
J. Cowles;H. Scheld;R. Lemay;C. Peterson
为第三次空间运输系统使命（STS-3）的飞行准备了四天大的松树幼苗以及绿豆和燕麦种子。将幼苗和种子种植在置于植物生长单元（PGU）中的六个微型生长室（每个物种两个室）中。制备另一组幼苗和种子并置于另一PGU中作为Ig对照。飞行PGU在发射前约11小时位于轨道飞行器中甲板储物柜区域。松树幼苗和发芽的绿豆和燕麦种子暴露于194小时的微重力。在着陆后约75分钟，在临时实验室接收PGU。在着陆点对植物进行了观察、拍照和大气气体分析。然后将植物带到我们的休斯顿实验室，在那里测量和分析木质素和蛋白质含量以及苯丙氨酸解氨酶（PAL）和过氧化物酶活性。飞行幼苗短于所有三个物种的控制。绿豆和燕麦的根中有25%到40%向上生长，绿豆显示出迷失方向的迹象。飞行绿豆表现出显着降低木质素含量与对照相比，PAL和过氧化物酶活性降低飞行松幼苗。结果普遍支持假设，木质素合成减少在近失重状态下，并显示其他有趣的发现。
Four-day-old pine seedlings and mung bean and oat seeds were prepared for flight on the third Space Transport System Mission (STS-3). The seedlings and seeds were planted in six mini-growth chambers (two chambers per species) which were placed in a plant growth unit (PGU). Another set of seedlings and seeds was prepared and placed in another PGU as the 1 g control. The flight PGU was positioned in the orbiter mid-deck locker area about 11 h prior to launch. The pine seedlings and germinating mung bean and oat seeds were exposed to 194 h of microgravity. The PGU was received at a temporary laboratory about 75 min post-landing. Plants were observed, photographed and the atmospheric gases analyzed at the landing site. The plants were then brought to our Houston laboratory where they were measured and analyzed for lignin and protein content and for phenylalanine ammonia-lyase (PAL) and peroxidase activities. Flight seedlings were shorter than the controls in all three species. Twenty-five to 40 per cent of the mung bean and oat roots were growing upward, and the mung beans showed signs of disorientation. Flight mung beans showed a significant reduction in lignin content in comparison to the controls, and PAL and peroxidase activities were reduced in flight pine seedlings. The results generally support the postulate that lignin synthesis is reduced in near-weightlessness and show other interesting findings.