FREEZING-INJURY AND ROOT DEVELOPMENT IN WINTER CEREALS
FREEZING-INJURY AND ROOT DEVELOPMENT IN WINTER CEREALS
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DOI：
10.1104/pp.73.3.773
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发表时间：
1983-01-01
期刊：
影响因子：
7.4
通讯作者：
FOWLER, DB
中科院分区：
文献类型：
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作者：
CHEN, THH;GUSTA, LV;FOWLER, DB
暴露于 2°C 时，黑麦 (SecalealesL.cv ‘Puma’) 和小麦 (Triticum aestivumL.cv ‘Norstar’ 和 ‘Cappelle’) 的叶和冠的抗寒性增加，而根部的抗寒性几乎没有变化。冷冻至-11°C或更低并移植到土壤中的冷硬化Norstar小麦植株的根和芽生长均严重下降。相比之下，在营养琼脂培养基中生长并经历相同硬化和冷冻条件的植物的芽生长不受-20°C冷冻温度的影响，而根生长在-15°C下减少。因此，很明显，根部发育不足限制了植物在自然条件下冷冻生存的能力。一般来说，通过电导率法测定的50%植物被杀死的温度低于通过再生获得的温度。对于这种差异的一个简单解释是，冠部的大多数细胞仍然存活，而对再生至关重要的一小部分细胞受伤或死亡。在补充有每升 3 毫克 2,4-二氯苯氧乙酸的 B-5 液体培养基中生长的 Norstar 小麦悬浮培养物可以冷硬化至与土壤生长植物相同的水平。当这些培养物转移到补充有低浓度 2,4-二氯苯氧基乙酸（<1 毫克/升）的相同生长培养基中时，这些培养物会产生根。当冷冻至-15°C时，培养物的再生长是对照的50%，而在冷冻至-11°C的培养物中，具有根发育的愈伤组织的百分比降低了50%。这些结果表明冷冻会影响根的形态发生，而不仅仅是杀死负责根再生的细胞。
Upon exposure to 2°C, the leaves and crowns of rye (Secale cerealeL. cv `Puma') and wheat (Triticum aestivumL. cv `Norstar' and `Cappelle') increased in cold hardiness, whereas little change in root cold hardiness was observed. Both root and shoot growth were severely reduced in cold-hardened Norstar wheat plants frozen to −11°C or lower and transplanted to soil. In contrast, shoot growth of plants grown in a nutrient agar medium and subjected to the same hardening and freezing conditions was not affected by freezing temperatures of −20°C while root growth was reduced at −15°C. Thus, it was apparent that lack of root development limited the ability of plants to survive freezing under natural conditions.Generally, the temperatures at which 50% of the plants were killed as determined by the conductivity method were lower than those obtained by regrowth. A simple explanation for this difference is that the majority of cells in the crown are still alive while a small portion of the cells which are critical for regrowth are injured or killed.Suspension cultures of Norstar wheat grown in B-5 liquid medium supplemented with 3 milligrams per liter of 2,4-dichlorophenoxyacetic acid could be cold hardened to the same levels as soil growth plants. These cultures produce roots when transferred to the same growth medium supplemented with a low rate of 2,4-dichlorophenoxyacetic acid (<1 milligram per liter). When frozen to −15°C regrowth of cultures was 50% of the control, whereas the percentage of calli with root development was reduced 50% in cultures frozen to −11°C. These results suggest that freezing affects root morphogenesis rather than just killing the cells responsible for root regeneration.