Phenylpropanoid compounds and disease resistance in transgenic tobacco with altered expression of L-phenylalanine ammonia-lyase
Phenylpropanoid compounds and disease resistance in transgenic tobacco with altered expression of L-phenylalanine ammonia-lyase
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DOI：
10.1016/s0031-9422(03)00151-1
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发表时间：
2003-09-01
期刊：
影响因子：
3.8
通讯作者：
Dixon, RA
中科院分区：
文献类型：
--
作者：
Shadle, GL;Wesley, SV;Dixon, RA
过量表达l -苯丙氨酸解氨酶（PAL(+)）的烟草植株产生高水平的绿原酸（CGA），对烟草Cercospora nicotianae真菌感染的敏感性显著降低，但对烟草花叶病毒（TMV）的抗性不变。信号分子水杨酸（SA）在未感染的PAL（+）和对照植物以及TMV感染后的水平相似。在PAL（+）烟草与携带细菌NahG水杨酸羟化酶基因的烟草杂交中，携带两种基因的后代对TMV的抗性都丧失了，这表明SA对TMV的抗性至关重要，CGA等苯丙类化合物的增加不能替代SA水平的降低。与NahG亲本相比，PAL(+)/NahG组合的植株对烟草Cercospora nicotianae的敏感性明显降低。这些结果与最近一篇质疑PAL在拟南芥SA生物合成中的作用的报道一致，并强调了苯丙类化合物（如CGA）在植物抗病中的重要性。(C) 2003 Elsevier Ltd.版权所有。
Tobacco plants over-expressing L-phenylalanine ammonia-lyase (PAL(+)) produce high levels of chlorogenic acid (CGA) and exhibit markedly reduced susceptibility to infection with the fungal pathogen Cercospora nicotianae, although their resistance to tobacco mosaic virus (TMV) is unchanged. Levels of the signal molecule salicylic acid (SA) were similar in uninfected PAL(+) and control plants and also following TMV infection. In crosses of PAL(+) tobacco with tobacco harboring the bacterial NahG salicylate hydroxylase gene, progeny harboring both transgenes lost resistance to TMV, indicating that SA is critical for resistance to TMV and that increased production of phenylpropanoid compounds such as CGA cannot substitute for the reduction in SA levels. In contrast, PAL(+)/NahG plants showed strongly reduced susceptibility to Cercospora nicotianae compared to the NahG parent line. These results are consistent with a recent report questioning the role of PAL in SA biosynthesis in Arabidopsis, and highlight the importance of phenylpropanoid compounds such as CGA in plant disease resistance. (C) 2003 Elsevier Ltd. All rights reserved.