Backer Robert, Mahomed Waheed, Reeksting Bianca J, Engelbrecht Juanita, Ibarra-Laclette Enrique, van den Berg Noëlani
Forestry and Agricultural Biotechnology Institute, University of Pretoria Pretoria, South Africa ; Department of Genetics, Fruit Tree Biotechnology Program, University of Pretoria Pretoria, South Africa.
Laboratorio Nacional de Genómica para la Biodiversidad-Langebio/Unidad de Genómica Avanzada, Centro de Investigación y Estudios Avanzados del - Instituto Politécnico Nacional Irapuato, México ; Red de Estudios Moleculares Avanzados, Instituto de Ecología A.C., Xalapa, México.
Front Plant Sci. 2015 Apr 29;6:300. doi: 10.3389/fpls.2015.00300. eCollection 2015.
The NONEXPRESSOR OF PATHOGENESIS-RELATED GENES1 (NPR1) forms an integral part of the salicylic acid (SA) pathway in plants and is involved in cross-talk between the SA and jasmonic acid/ethylene (JA/ET) pathways. Therefore, NPR1 is essential to the effective response of plants to pathogens. Avocado (Persea americana) is a commercially important crop worldwide. Significant losses in production result from Phytophthora root rot, caused by the hemibiotroph, Phytophthora cinnamomi. This oomycete infects the feeder roots of avocado trees leading to an overall decline in health and eventual death. The interaction between avocado and P. cinnamomi is poorly understood and as such limited control strategies exist. Thus uncovering the role of NPR1 in avocado could provide novel insights into the avocado - P. cinnamomi interaction. A total of five NPR1-like sequences were identified. These sequences were annotated using FGENESH and a maximum-likelihood tree was constructed using 34 NPR1-like protein sequences from other plant species. The conserved protein domains and functional motifs of these sequences were predicted. Reverse transcription quantitative PCR was used to analyze the expression of the five NPR1-like sequences in the roots of avocado after treatment with salicylic and jasmonic acid, P. cinnamomi infection, across different tissues and in P. cinnamomi infected tolerant and susceptible rootstocks. Of the five NPR1-like sequences three have strong support for a defensive role while two are most likely involved in development. Significant differences in the expression profiles of these five NPR1-like genes were observed, assisting in functional classification. Understanding the interaction of avocado and P. cinnamomi is essential to developing new control strategies. This work enables further classification of these genes by means of functional annotation and is a crucial step in understanding the role of NPR1 during P. cinnamomi infection.
病程相关基因非表达子1（NPR1）是植物水杨酸（SA）途径的一个组成部分，参与SA与茉莉酸/乙烯（JA/ET）途径之间的相互作用。因此，NPR1对于植物对病原体的有效反应至关重要。鳄梨（Persea americana）是全球一种具有重要商业价值的作物。由半活体营养型樟疫霉（Phytophthora cinnamomi）引起的根腐病导致了严重的生产损失。这种卵菌感染鳄梨树的须根，导致树体整体健康状况下降并最终死亡。鳄梨与樟疫霉之间的相互作用尚不清楚，因此可用的控制策略有限。因此，揭示NPR1在鳄梨中的作用可能为鳄梨 - 樟疫霉的相互作用提供新的见解。共鉴定出5个类NPR1序列。使用FGENESH对这些序列进行注释，并使用来自其他植物物种的34个类NPR1蛋白序列构建最大似然树。预测了这些序列的保守蛋白结构域和功能基序。采用逆转录定量PCR分析了5个类NPR1序列在水杨酸和茉莉酸处理后、樟疫霉感染后、不同组织以及樟疫霉感染的耐病和感病砧木的鳄梨根中的表达情况。在这5个类NPR1序列中，有3个对防御作用有有力支持，而另外2个最有可能参与发育过程。观察到这5个类NPR1基因的表达谱存在显著差异，有助于功能分类。了解鳄梨与樟疫霉的相互作用对于制定新的控制策略至关重要。这项工作通过功能注释能够对这些基因进行进一步分类，是了解NPR1在樟疫霉感染过程中作用的关键一步。
