Responses of In vitro-Grown Plantlets (Vitis vinifera) to Grapevine leafroll-Associated Virus-3 and PEG-Induced Drought Stress

Abstract

Stresses caused by viral diseases and drought have long threatened sustainable production of grapevine. These two stresses frequently occur simultaneously in many of grapevine growing regions of the world. We studied responses of in vitro-grown plantlets (Vitis vinifera) to Grapevine leafroll associated virus-3 (GLRaV-3) and PEG-induced drought stress. Results showed that stress induced by either virus infection or drought had negative effects on vegetative growth, caused significant decreases and increases in total soluble protein and free proline, respectively, induced obvious cell membrane damage and cell death, and markedly increased accumulations of O2·- and H2O2. Co-stress by virus and drought had much severer effects than single stress on the said parameters. Virus infection alone did not cause significant alternations in activities of POD, ROS, and SOD, and contents of MDA, which, however, markedly increased in the plantlets when grown under single drought stress and co-stress by the virus and drought. Levels of ABA increased, while those of IAA decreased in the plantlets stressed by virus infection or drought. Simultaneous stresses by the virus and drought had co-effects on the levels of ABA and IAA. Up-regulation of expressions of ABA biosynthesis genes and down-regulation of expressions of IAA biosynthesis genes were responsible for the alternations of ABA and IAA levels induced by either the virus infection or drought stress and co-stress by them. Experimental strategies established in the present study using in vitro system facilitate investigations on ‘pure’ biotic and abiotic stress on plants. The results obtained here provide new insights into adverse effects of stress induced by virus and drought, in single and particularly their combination, on plants, and allow us to re-orientate agricultural managements toward sustainable development of the agriculture.

Development, histological observations and Grapevine leafroll‐associated virus‐3 localisation in in vitro grapevine micrografts

“…Both healthy and GLRaV‐3 infected in vitro stock shoots were established according to Cui et al . (, ) and maintained on a shoot maintaining medium (SMM) containing half‐strength Murashige & Skoog () medium (MS) supplemented with 30 g L −1 sucrose and 7 g L −1 agar. The pH of the medium was adjusted to 5.8 prior to autoclaving at 121°C for 20 min, as described by Cui et al .…”

Effects of PEG-induced drought stress on regulation of indole alkaloid biosynthesis in Catharanthus roseus

“…In addition to this, antioxidant mechanisms also help plants equipped with antioxidant molecules, including superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD), to survive under stress conditions (Prochazkova et al 2001). For the past several years, many efforts to have focused on testing the C. roseus' drought stress tolerance capacity (Qureshi et al 2005;Cui et al 2016), but little information is obtained about the physiological basis and molecular mechanisms underlying the PRO and POD metabolism under drought stress in C. roseus.…”

Exogenous application of melatonin improves eradication of apple stem grooving virus from the infected in vitro shoots by shoot tip culture

“…The dried fraction containing IAA was injected into the HPLC system for measurements, as described by Cui et al . ().…”

“…Standard IAA was provided by Sigma and used to monitor the losses during purification. The extraction and purification of IAA were conducted according to Cui et al (2016). The purified extract solution was transferred into 2 mL centrifuge tubes containing 0.3 g polyvinylpolypyrrolidone (PVPP) and then kept at À20°C for the measurements of IAA in a Breeze HPLC system (Waters 2489 UV/visible detector), using wavelength of 254 nm, velocity of 0.7 mL min À1 , sample quantity of 10 lM and column temperature of 30°C.…”

“…The purified extract solution was transferred into 2 mL centrifuge tubes containing 0.3 g polyvinylpolypyrrolidone (PVPP) and then kept at À20°C for the measurements of IAA in a Breeze HPLC system (Waters 2489 UV/visible detector), using wavelength of 254 nm, velocity of 0.7 mL min À1 , sample quantity of 10 lM and column temperature of 30°C. The dried fraction containing IAA was injected into the HPLC system for measurements, as described by Cui et al (2016).…”