Identification of a new member of the WRKY family in tobacco. Involved in ozone-induced gene regulation?

Abstract

GSF -Na tional Re search Cen ter for En vi ron ment and Health, In sti tute of Bio chem i cal Plant Pa thol ogy, Re cent stud ies showed, that ozone-in duced gene ex pres sion oc curs via at least two dif fer ent sig nal ling mech a nisms that are eth yl ene-de pend ent (ß-1,3-glucanases) and eth yl ene-in de pend ent in de pend ent (stilbene synthase). To iden tify trans-act ing fac tors in volved in ozone-in duced gene ex pres sion we an alyzed a 150 bp PCR frag ment of an ozone-re spon sive pro moter seg ment of the grape vine resveratrol synthase gene (Vst1) in com bi na tion of a cDNA li brary pre pared from ozone-treated to bacco plants, us ing the yeast one-hy brid screen ing sys tem. Two cDNA clones that en code WRKY bind ing pro teins were iso lated by this screen ing tech nique. The open read ing frame of NtWRKY10 and NtWRKY11 showed an iden tity of 93.5 % and the de duced amino acid se quence an iden tity of 89.3 %. Ac cord ing to the WRKY do main clas si fi ca tion in Arabidopsis, both pro teins be long to sub group II. Com par i son with known to bacco WRKY pro teins in di cate that WRKY10 and WRKY11 be long to a new class of to bacco WRKY tran scription fac tors. Elec tro pho retic mo bil ity shift as says (EMSA) of yeast ex tracts, con tain ing the WRKY fu sion pro tein showed a weak bind ing to the ra dio ac tively la belled 150 bp ozone-respon sive Vst1 frag ment. These re sults are con sis tent with an in volve ment of WRKY pro teins in ozone-in duced phytoalexin gene ex pres sion.List of ab bre vi a tions: Vst1 -resveratrol synthase gene; EMSA -elec tro pho retic mo bil ity shift as say In tro duc tionStrato spheric ozone pro tects life from det ri men tal ul tra vi o let-B ra di a tion, but tro po spheric ozone is a se ri ous world-wide pol lut ant (Krupa 2000). The phytotoxic ef fects of ozone were rec og nized as early as 1950, and sub se quent stud ies have shown the dam ag ing ef fects of ozone at the phys i o log i cal, bio chem i cal and ge netic level (Runeckles and Chevo ne 1992, Kangasjärvi et al. 1994, Sandermann 1996).The spe cific mech a nisms by which ozone causes changes in plant gene ex pres sion are not known, but it is gen er ally ac cepted that ozone ini ti ates an ox i da tive burst and an ac tive pro duc tion of re ac tive ox y gen in ter me di ates (Schraudner et al. 1998, Pellinen et al. 1999, Rao and Da vis 1999. Sev eral signal mol e cules like eth yl ene, jasmonic acid and sal icylic acid, have been hy poth e sized to act as a second or third mes sen ger for ozone-in duced gene expres sion (Mehlhorn and

Ozone-triggered surface uptake and stress volatile emissions in Nicotiana tabacum ‘Wisconsin’

“…Nicotiana tabacum L. is an annual herb that has terpene-filled glandular trichomes on leaf surface and has therefore been used as a model species for ozone-plant surface reactions (Jud et al ., 2016). There have been several studies looking at the physiological impact of ozone on N. tabacum (Beauchamp et al ., 2005; Cheng and Sun, 2013; Eltayeb et al ., 2006; Heidenreich et al ., 2006; Janzik et al ., 2005; Mancini et al ., 2006; Pasqualini et al ., 2009; Samuel et al ., 2005; Silva et al ., 2012), but the majority of studies have mainly focused on short-term immediate stress responses rather than considered the full response from exposure through the recovery. There is also a lack of knowledge of how the emissions of the lipoxygenase pathway (LOX volatiles, also called green leaf volatiles), mono- and sesquiterpenes are regulated upon acute ozone doses from exposure through recovery and their relationship with foliage surface ozone uptake and elicitation rate.…”

Ozone treatments to induce systemic-acquired resistance in leaves of potted vines: molecular responses and NIR evaluation for identifying effective dose and exposition duration

“…Indeed, the over-expression of resistance-related genes after O 3 exposition has been reported in different species (Sharma et al, 1996;Heath, 2008). Therefore, O 3 has been studied not only as an air pollutant, but also as an abiotic elicitor for different crops and plants (Sharma et al, 1996;Sandermann et al, 1998;Heidenreich et al, 2006;Modesti et al, 2018). To study the possible SAR activation, the expression level of resistance-related genes was determined in the present study.…”

Differences in Ozone Sensitivity at Different NPK Levels of Three Tropical Varieties of Mustard (Brassica campestris L.): Photosynthetic Pigments, Metabolites, and Antioxidants

“…The response of plants is complex and multifunctional towards O 3 exposure (Heidenreich et al 2006;Li et al 2006). After entry into the plant tissue, O 3 leads to various biochemical events.…”