Shan Xue Chan, Goodwin Paul H
Department of Environmental Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada.
Funct Plant Biol. 2005 May;32(3):259-266. doi: 10.1071/FP04190.
A SAR8.2 gene, NbSAR8.2m, was obtained from a PCR-selected cDNA subtraction library constructed from mRNA of Nicotiana benthamiana Domin. infected with Colletotrichum orbiculare (Berk & Mont.) von Arx. It is the first SAR8.2 gene described from N. benthamiana and shows relatively high similarity in both the coding and 3'-UTR to NtSAR8.2m of Nicotiana tabacum L. Expression of NbSAR8.2m occurred in healthy plants but was induced 8-fold following infection by C. orbiculare. Virus-induced gene silencing of NbSAR8.2m reduced its expression and resulted in the development of disease symptoms 24 h earlier than in control plants, indicating that NbSAR8.2m affects the length of the biotrophic phase of infection. Both NtSAR8.2m and NbSAR8.2m are unique among the SAR8.2 genes in that they encode for four cysteines near the C-terminus. The conserved cysteines of SAR8.2 genes may indicate roles in stress responses, defence reactions, metal ion homeostasis or other processes.
从感染了圆形炭疽菌（Berk & Mont.）von Arx的本氏烟草（Nicotiana benthamiana Domin.）mRNA构建的PCR筛选cDNA消减文库中获得了一个SAR8.2基因，NbSAR8.2m。它是从本氏烟草中描述的首个SAR8.2基因，在编码区和3'-UTR与烟草（Nicotiana tabacum L.）的NtSAR8.2m均显示出较高的相似性。NbSAR8.2m在健康植物中表达，但在被圆形炭疽菌感染后表达量诱导增加了8倍。NbSAR8.2m的病毒诱导基因沉默降低了其表达，并导致疾病症状比对照植物提前24小时出现，表明NbSAR8.2m影响感染的活体营养阶段的时长。NtSAR8.2m和NbSAR8.2m在SAR8.2基因中是独特的，因为它们在C末端附近编码四个半胱氨酸。SAR8.2基因中保守的半胱氨酸可能表明其在应激反应、防御反应、金属离子稳态或其他过程中发挥作用。
