Eucalyptus ESTs corresponding to the enzyme glutamine synthetase and the protein D1, sites of action of herbicides that cause oxidative stress

Abstract

This work was aimed at locating Eucalyptus ESTs corresponding to the GS enzyme (Glutamine Synthetase, EC = 6.3.1.2) and to the D1 protein, which are directly related to resistance to herbicides that promote oxidative stress. Glutamine Synthetase corresponds to the site of action of the herbicide glufosinate. Herbicides that belong to groups such as ureas, uracils, triazines and triazinones act on the D1-Qb complex (receptor of electrons from the Photosystem II) by inactivating it. The clusters EGEQRT3302E01.g, EGEQRT3001F12.b; EGEZLV1203B04.g; EGBGFB1211H06.g and EGEZLV1205F09.g enclosed complete sequences (with 356 amino acids) of the Glutamine Synthetase enzyme. The cluster EGEQSL1054G06.g is a consensus of four reads and enclosed a complete sequence of D1 Protein (with 353 amino acids). The comparison of the sequences of Protein D1 from different species showed that the substitutions of serine (S) by glycine (G) or serine (S) by threonine (T) at the position 264 could produce plants resistant to herbicides that act on electron flow on Photosystem II. The sequence of amino acids corresponding to the cluster EGEQSL1054G06.g had a serine in position 264 indicating sensitivity of the Eucalyptus plants to herbicides that act on this site.

<i>Conyza sumatrensis</i> Intrapopulation Variation in Response to Glufosinate

“…Like glyphosate, glufosinate is a non-selective herbicide that is applied post-emergence [17]. While glyphosate inhibits 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS), glufosinate inhibits glutamine synthetase (GS) [18], an enzyme that facilitates the rate-limiting step in nitrogen assimilation in plants [19]. Inhibition of GS results in the rapid accumulation of intracellular ammonium [20], and the concomitant depletion of glutamine and various other amino acids in the plant [21].…”

Variation in the Sensitivities of Hairy Beggarticks (Bidens pilosa) Plants and Their Progenies to Glufosinate Ammonium

“…Glufosinate ammonium is the common name for ammonium-DL-homoalanin-4-yl(methyl)phosphinate (International Union of Pure and Applied Chemistry), Chemical Abstract Service number 77182-82-2 (Food and Agriculture Organization [FAO]/World Health Organization [WHO] 2013), a nonselective herbicide used in POST applications for the control of a broad spectrum of broadleaf and grassy weeds (American Hoechst Corporation 1982). The only commercially available herbicide that acts on glutamine synthetase (Velini et al 2005), glufosinate ammonium is the synthetic version of phosphinothricin (Lydon and Duke 1999), a product of bialaphos decomposition that was first isolated from Streptomyces viridochromogenes or Streptomyces hygroscopicus (Hoerlein 1994).…”