Molecular Basis of Citrus sunki Susceptibility and Poncirus trifoliata Resistance Upon Phytophthora parasitica Attack

Abstract

Coevolution has shaped the molecular basis of an extensive number of defense mechanisms in plant-pathogen interactions. Phytophthora parasitica, a hemibiothrophic oomycete pathogen and the causal agent of citrus root rot and gummosis, interacts differently with Citrus sunki and Poncirus trifoliata, two commonly favored citrus rootstocks that are recognized as susceptible and resistant, respectively, to P. parasitica. The molecular core of these interactions remains elusive. Here, we provide evidence on the defense strategies employed by both susceptible and resistant citrus rootstocks, in parallel with P. parasitica deployment of effectors. Time course expression analysis (quantitative real-time polymerase chain reaction) of several defense-related genes were evaluated during i) plant disease development, ii) necrosis, and iii) pathogen effector gene expression. In C. sunki, P. parasitica deploys effectors, including elicitins, NPP1 (necrosis-inducing Phytophthora protein 1), CBEL (cellulose-binding elicitor and lectin activity), RxLR, and CRN (crinkler), and, consequently, this susceptible plant activates its main defense signaling pathways that result in the hypersensitive response and necrosis. Despite the strong plant-defense response, it fails to withstand P. parasitica invasion, confirming its hemibiothrophic lifestyle. In Poncirus trifoliata, the effectors were strongly expressed, nevertheless failing to induce any immunity manipulation and disease development, suggesting a nonhost resistance type, in which the plant relies on preformed biochemical and anatomical barriers.

Mikan Genome Database (MiGD): integrated database of genome annotation, genomic diversity, and CAPS marker information for mandarin molecular breeding

“…Elucidation of whole-genome sequences is a key milestone for research to explore agronomically and academically important traits specific to the trifoliate orange such as various disease resistances for Phytophthora citrophthora, CTV, Tylenchulus semipenetrans, coldhardiness, the aptitude of root stock, and so on. Recently, various research efforts are underway to elucidate the molecular mechanisms and identify the causative gene for cold stress tolerance (Wang et al 2015), Huanglongbing tolerance (Rawat et al 2017), Phytophthora disease resistance (Dalio et al 2018) and so on. The genomic resources of P. trifoliata in MiGD can contribute to find functional mutations on the genome structure and the specific genes responsible for them.…”

Tea Tree Oil Induces Systemic Resistance against Fusarium wilt in Banana and Xanthomonas Infection in Tomato Plants

“…Total mRNA was reverse transcribed by using oligo-dT primers in a 20 µL reaction volume by using RevertAid First Strand cDNA Synthesis Kit (Thermo Fisher Scientific) and 1 µg total DNA-free RNA. cDNA was diluted (1:20), and 1 µL of the diluted cDNA was used in a 13 µL reaction volume containing 6.75 µL of Go-Taq qPCR Master mix, and 0.75 µM (1 µL) of each primer [ 44 , 46 ].…”

Taxtomina parcialmente purificada e preparações de >i<Streptomyces scabies>/i< na indução de resistência em soja à >i<Phakopsora pachyrhizi>/i<

“…Crédito do infográfico: Marcelo Madalosso -Instituto Phytus ..................................................................................... 23 Figura 3: Genes relacionados a ácido salicílico, jasmonato, etileno, genes R, explosão oxidativa, fisiologia e reprodução. Adaptado de Dalio et al (2018) Figura 9: Severidade em folhas destacadas de soja 12 dias após a inoculação com urediniósporos de Phakopsora pachyrhizi previamente tratados com o controle negativo e taxtomina parcialmente purificada em diferentes intervalos de tempo. Médias seguidas pela mesma letra não diferiram entre si no teste t-Student a p 0,05.…”

“…Dentre os genes que podem ser monitorados, estão o MeSA, NPR1 e PR1 relacionados a via do ácido salicílico (Figura 3). Também pode-se monitorar a expressão do gene MYC2 relacionado a via do jasmonato e os genes ACC e ERF1 relacionados a via do etileno (Dalio et al 2018). O monitoramento de tais genes se torna importante a medida que durante a infecção por um patógeno, diferentes fitormônios podem ser induzidos e agir como moléculas sinalizadoras para desencadear a produção de compostos antimicrobianos (Verma et al 2016).…”

“…Figura 3: Genes relacionados a ácido salicílico, jasmonato, etileno, genes R, explosão oxidativa, fisiologia e reprodução. Adaptado de Dalio et al (2018).…”