Papenbrock J, Riemenschneider A, Kamp A, Schulz-Vogt H N, Schmidt A
Institut für Botanik, Universität Hannover, Herrenhäuser Strasse 2, 30419 Hannover, Germany.
Plant Biol (Stuttg). 2007 Sep;9(5):582-8. doi: 10.1055/s-2007-965424.
Due to the clean air acts and subsequent reduction of emission of gaseous sulfur compounds sulfur deficiency became one of the major nutrient disorders in Northern Europe. Typical sulfur deficiency symptoms can be diagnosed. Especially plants of the Cruciferae family are more susceptible against pathogen attack. Sulfur fertilization can in part recover or even increase resistance against pathogens in comparison to sulfur-deficient plants. The term sulfur-induced resistance (SIR) was introduced, however, the molecular basis for SIR is largely unknown. There are several sulfur-containing compounds in plants which might be involved in SIR, such as high levels of thiols, glucosinolates, cysteine-rich proteins, phytoalexins, elemental sulfur, or H2S. Probably more than one strategy is used by plants. Species- or even variety-dependent differences in the development of SIR are probably used. Our research focussed mainly on the release of H2S as defence strategy. In field experiments using different BRASSICA NAPUS genotypes it was shown that the genetic differences among BRASSICA genotypes lead to differences in sulfur content and L-cysteine desulfhydrase activity. Another field experiment demonstrated that sulfur supply and infection with PYRENOPEZIZA BRASSICA influenced L-cysteine desulfhydrase activity in BRASSICA NAPUS. Cysteine-degrading enzymes such as cysteine desulfhydrases are hypothesized to be involved in H2S release. Several L- and D-cysteine-specific desulfhydrase candidates have been isolated and partially analyzed from the model plant ARABIDOPSIS THALIANA. However, it cannot be excluded that H2S is also released in a partial back reaction of O-acetyl-L-serine(thiol)lyase or enzymes not yet characterized. For the exact determination of the H2S concentration in the cell a H2S-specific microsensor was used the first time for plant cells. The transfer of the results obtained for application back on BRASSICA was initiated.
由于《清洁空气法》以及随后气态硫化合物排放量的减少，硫缺乏成为北欧主要的养分失调问题之一。典型的硫缺乏症状可以被诊断出来。尤其是十字花科植物更容易受到病原体攻击。与缺硫植物相比，施硫可以部分恢复甚至提高对病原体的抗性。“硫诱导抗性（SIR）”这一术语被提出，然而，SIR的分子基础在很大程度上尚不清楚。植物中有几种含硫化合物可能与SIR有关，如高水平的硫醇、芥子油苷、富含半胱氨酸的蛋白质、植保素、元素硫或H₂S。植物可能使用不止一种策略。SIR的发展可能存在物种甚至品种依赖性差异。我们的研究主要集中在H₂S的释放作为防御策略。在使用不同甘蓝型油菜基因型的田间试验中表明，甘蓝型油菜基因型之间的遗传差异导致硫含量和L-半胱氨酸脱硫酶活性存在差异。另一个田间试验表明，硫供应和感染芸苔链格孢会影响甘蓝型油菜中L-半胱氨酸脱硫酶的活性。诸如半胱氨酸脱硫酶之类的半胱氨酸降解酶被推测参与H₂S的释放。已经从模式植物拟南芥中分离并部分分析了几种L-和D-半胱氨酸特异性脱硫酶候选物。然而，不能排除H₂S也在O-乙酰-L-丝氨酸（硫醇）裂解酶或尚未鉴定的酶的部分逆反应中释放。为了精确测定细胞中的H₂S浓度，首次将H₂S特异性微传感器用于植物细胞。已着手将应用中获得的结果反馈到甘蓝型油菜上。
