Ton Jurriaan, Mauch-Mani Brigitte
Laboratory of Biochemistry and Molecular Biology, Department of Science, Institute of Botany, University of Neuchâtel, Rue Emile-Argand 9, PO Box 2, CH-2007 Neuchâtel, Switzerland.
Plant J. 2004 Apr;38(1):119-30. doi: 10.1111/j.1365-313X.2004.02028.x.
The non-protein amino acid beta-amino-butyric acid (BABA) protects plants against a wide range of pathogens. We have examined the effectiveness and mode of action of BABA on resistance against two necrotrophic pathogens. Treatment of Arabidopsis with BABA induced resistance against Alternaria brassicicola and Plectosphaerella cucumerina to a similar level by jasmonic acid (JA). Conversely, treatment with benzothiadiazole (BTH), a functional analogue of salicylic acid (SA), had no significant effect on the resistance against both pathogens. BABA-induced resistance against A. brassicicola and P. cucumerina was unaffected in the JA-insensitive mutant coi1-1 and the camalexin-deficient mutant pad3-1. Moreover, the expression of BABA-induced resistance was not associated with enhanced accumulation of camalexin or enhanced transcription of the JA-inducible PDF1.2 gene. The expression of BABA-induced resistance against P. cucumerina was unaffected in mutants impaired in ethylene (ET) and SA signalling, but was blocked in the abscisic acid (ABA)-deficient mutant aba1-5, the ABA-insensitive mutant abi4-1 and the callose-deficient mutant pmr4-1. Upon infection by both pathogens, BABA-treated plants showed an earlier and more pronounced accumulation of callose. Treatment with the callose-inhibitor 2-deoxy-D-glucose (2-DDG) reversed the BABA-induced resistance against A. brassicicola. Furthermore, primed callose deposition was absent in BABA-treated abi4-1 and pmr4-1 plants upon infection by P. cucumerina. Although the expression of BABA-induced resistance was not associated with enhanced transcription of the ABA-inducible RAB18 gene, application of ABA mimicked the effect of BABA on the level of callose accumulation and resistance. Hence, BABA-induced resistance against necrotrophic pathogens is based on primed callose accumulation, which is controlled by an ABA-dependent defence pathway.
非蛋白质氨基酸β-氨基丁酸（BABA）可保护植物抵御多种病原体。我们研究了BABA对两种坏死性病原体抗性的有效性及作用方式。用BABA处理拟南芥可诱导对链格孢属甘蓝链格孢和黄瓜盘梗霉的抗性，其抗性水平与茉莉酸（JA）诱导的相似。相反，用苯并噻二唑（BTH）（水杨酸（SA）的功能类似物）处理对这两种病原体的抗性没有显著影响。BABA诱导的对甘蓝链格孢和黄瓜盘梗霉的抗性在JA不敏感突变体coi1-1和缺乏抗菌肽的突变体pad3-1中不受影响。此外，BABA诱导抗性的表达与抗菌肽积累的增加或JA诱导的PDF1.2基因转录的增强无关。BABA诱导的对黄瓜盘梗霉抗性的表达在乙烯（ET）和SA信号传导受损的突变体中不受影响，但在脱落酸（ABA）缺陷突变体aba1-5、ABA不敏感突变体abi4-1和胼胝质缺陷突变体pmr4-1中被阻断。在受到两种病原体感染时，用BABA处理的植物显示胼胝质积累更早且更明显。用胼胝质抑制剂2-脱氧-D-葡萄糖（2-DDG）处理可逆转BABA诱导的对甘蓝链格孢的抗性。此外，在用BABA处理的abi4-1和pmr4-1植物中，受到黄瓜盘梗霉感染时不存在引发的胼胝质沉积。虽然BABA诱导抗性的表达与ABA诱导的RAB18基因转录增强无关，但ABA的应用模拟了BABA对胼胝质积累水平和抗性的影响。因此，BABA诱导的对坏死性病原体的抗性基于引发的胼胝质积累，这由一条ABA依赖的防御途径控制。
