Pan Jian-Wei, Ye Dan, Wang Li-Ling, Hua Jing, Zhao Gu-Feng, Pan Wei-Huai, Han Ning, Zhu Mu-Yuan
State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310012, People's Republic of China.
Plant Cell Physiol. 2004 Jun;45(6):751-60. doi: 10.1093/pcp/pch090.
In vivo and in vitro experiments showed that border cell (BC) survival was dependent on root tip mucigel in barley (Hordeum vulgare L. cv. Hang 981). In aeroponic culture, BC development was an induced process in barley, whereas in hydroponic culture, it was a kinetic equilibrium process during which 300-400 BCs were released into water daily. The response of root elongation to temperatures (10-35 degrees C) was very sensitive but temperature changes had no great effect on barley BC development. At 35 degrees C, the root elongation ceased whereas BC production still continued, indicating that the two processes might be regulated independently under high temperature (35 degrees C) stress. Fifty microM Al could inhibit significantly BC development by inhibiting pectin methylesterase activity in the root cap of cv. 2000-2 (Al-sensitive) and cv. Humai 16 (Al-tolerant), but 20 microM Al could not block BC development in cv. Humai 16. BCs and their mucigel of barley had a limited role in the protection of Al-induced inhibition of root elongation, but played a significant role in the prevention of Al from diffusing into the meristems of the root tip and the root cap. Together, these results suggested that BC development was a temperature-insensitive but Al-sensitive process, and that BCs and their mucigel played an important role in the protection of root tip and root cap meristems from Al toxicity.
体内和体外实验表明，在大麦（Hordeum vulgare L. cv. Hang 981）中，边缘细胞（BC）的存活依赖于根尖黏液。在气培条件下，大麦中BC的发育是一个诱导过程，而在水培条件下，它是一个动态平衡过程，在此过程中每天有300 - 400个BC释放到水中。根伸长对温度（10 - 35摄氏度）的响应非常敏感，但温度变化对大麦BC的发育影响不大。在35摄氏度时，根伸长停止，而BC的产生仍在继续，这表明在高温（35摄氏度）胁迫下这两个过程可能是独立调节的。50微摩尔的铝可以通过抑制cv. 2000 - 2（铝敏感型）和cv. 淮麦16（铝耐受型）根冠中的果胶甲酯酶活性，显著抑制BC的发育，但20微摩尔的铝不能阻止cv. 淮麦16中BC的发育。大麦的BC及其黏液在保护铝诱导的根伸长抑制方面作用有限，但在防止铝扩散到根尖和根冠的分生组织中起重要作用。总之，这些结果表明BC的发育是一个对温度不敏感但对铝敏感的过程，并且BC及其黏液在保护根尖和根冠分生组织免受铝毒害方面起重要作用。
