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.
Highlights
Four herbicide action mechanisms are known to cause plant death by promoting oxidative stress: interference with the flow of electrons of Photosystem I, or Photosystem II, and action on the enzymes protoporphyrinogenIX oxidase (Protox or PPO, E.C. 1.3.3.4), or Glutamine Synthetase (GS, EC = 6.3.1.2)
This work aimed at studying Eucalyptus expressed sequence tags (ESTs) related to the action of herbicides on the flow of electrons in Photosystem II and the synthesis of glutamine
This work was aimed at locating Eucalyptus ESTs corresponding to GS enzymes (Glutamine Synthetase, EC = 6.3.1.2) and to the D1 protein, which are directly related to the action or resistance to herbicides, synthesis of porphyrins and photosynthetic activity in plants
Summary
Oxidative stress is associated with the production of highly reactive free radicals. These radicals are very effective in oxidizing lipids from cell membranes. This work aimed at studying Eucalyptus ESTs related to the action of herbicides on the flow of electrons in Photosystem II and the synthesis of glutamine. The action of diquat and paraquat is related to the electron flow deviation in photosystem I but their effects are not directly associated to the interaction with enzymes or proteins; for this reason, they should not be included in this work. The enzyme Protox, highly relevant for herbicide action and physiological modifications in plants, has been discussed in a separate paper
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
