Magnesium oxide nanoparticles induce systemic resistance in tomato against bacterial wilt disease

Abstract

Bacterial wilt is a serious problem affecting many important food crops. Recent studies have indicated that treatment with biotic or abiotic stress factors may increase the resistance of plants to bacterial infection. This study investigated the effects of magnesium oxide nanoparticles (MgO NP) on disease resistance in tomato plants against Ralstonia solanacearum, as well as its antibacterial activity. The roots of tomato seedlings were inoculated with R. solanacearum and then immediately treated with MgO NP; the treated plants showed very little inhibition of bacterial wilt. In contrast, when roots were drenched with a MgO NP suspension prior to inoculation with the pathogen, the incidence of disease was significantly reduced. Rapid generation of reactive oxygen species such as O 2À˙r adicals was observed in tomato roots treated with MgO NP. Further O 2 À˙w as rapidly generated when tomato plant extracts or polyphenols were added to the MgO NP suspension, suggesting that the generation of O 2 À˙i n tomato roots might be due to a reaction between MgO NP and polyphenols present in the roots. Salicylic acid-inducible PR1, jasmonic acid-inducible LoxA, ethylene-inducible Osm, and systemic resistance-related GluA were up-regulated in both the roots and hypocotyls of tomato plants after treatment of the plant roots with MgO NP. Histochemical analyses showed that b-1,3-glucanase and tyloses accumulated in the xylem and apoplast of pith tissues of the hypocotyls after MgO NP treatment. These results indicate that MgO NP induces systemic resistance in tomato plants against R. solanacearum.

MgO‐induced defence against bacterial wilt disease in Arabidopsis thaliana

“…Rapid production of reactive oxygen species (ROS) has been observed in tomato roots treated with MgO (Imada et al, 2016). Thus, ROS production was analysed in A. thaliana plants treated with MgO using diaminobenzidine (DAB), which detects hydrogen peroxide (H 2 O 2 ), one of several ROS.…”

“…In A. thaliana , ROS production is dependent on AtRBOHD, a member of the 10 RBOHs (RBOHA to J) that are homologous to NbRBOHB, which is triggered by both biotic and abiotic stresses leading to plant immunity (Liu & He, ). In a previous study (Imada et al ., ), rapid generation of ROS was observed in tomato roots treated with MgO, suggesting that ROS would be involved in MgO‐i DARS. The present study reveals how plant hormone and ROS signalling pathways influence MgO‐i DARS in A. thaliana .…”

“…SA signalling was required for rutin‐induced defence against pathogens in Nicotiana benthamiana (Yang et al ., ). In a previous study (Imada et al ., ), it was found that SA‐, JA‐, and ET‐inducible genes were systemically up‐regulated in MgO‐induced defence against R. solanacearum (MgO‐i DARS) in tomato plants. However, it has not been determined which plant hormone plays a pivotal role in MgO‐i DARS.…”

“…(Hyakumachi et al, 2013;Takahashi et al, 2014) and oomycetes such as Pythium oligandrum (Hase et al, 2006) and fungi such as Trichoderma harzianum (Jogaiah et al, 2013). Enhanced defence against R. solanacearum in host plants is also induced when the plants have been pretreated with abiotic agents such as silicon (Ghareeb et al, 2011), chitosan and silicon (Kiirika et al, 2013), DL-3-aminobutyric acid (Hassan & Abo-Elyousr, 2013), sclareol (Seo et al, 2012), rutin , Lhistidine (Seo et al, 2016) and magnesium oxide (Imada et al, 2016). These non-agrochemicals seem to have the potential for application in the field to control bacterial wilt disease because they have less damaging effects on the environment (Yuliar et al, 2015).…”

Genetic Diversity of <i>Fusarium solani</i> f. sp. <i>cucurbitae</i>, the Causal Root and Crown Rot of Cucurbits (Melon) by Using Molecular Markers and Control

“…[13] reported that the controlling effect increases in the administered dosage of nanoparticle and there exists a direct correlation between the administered dosage and controlling effect, the concentration of 2% MgoNps had the greatest effect in both liquid and solid media, [14] reported that the when roots were drenched with MgoNps suspension prior to inoculation with pathogen, the incidence of disease was significantly reduced. Also, these results agree with selko Dutch company research regarding close conformity with finding of [5].…”