A conditional marker gene allowing both positive and negative selection in plants

Abstract

Selectable markers enable transgenic plants or cells to be identified

Amino Acid Homeostasis Modulates Salicylic Acid–Associated Redox Status and Defense Responses inArabidopsis

“…However, a recent report using an in planta approach with 15 N-labeled amino acids demonstrated that LHT1 has a critical role in the uptake of L-Gln and L-Ala but not L-Lys (Svennerstam et al, 2007). In view of these contradictory results, we adapted an assay that uses D-enantiomeric amino acids (Erikson et al, 2004). D-enantiomers are generally toxic to plant cells but are thought to be taken up by the same transporters and with similar kinetics as their L-form counterparts (Erikson et al, 2004;Svennerstam et al, 2007;Forsum et al, 2008).…”

“…In view of these contradictory results, we adapted an assay that uses D-enantiomeric amino acids (Erikson et al, 2004). D-enantiomers are generally toxic to plant cells but are thought to be taken up by the same transporters and with similar kinetics as their L-form counterparts (Erikson et al, 2004;Svennerstam et al, 2007;Forsum et al, 2008). Our results showed that, although both lht1 and wild-type seeds germinated well on complete Murashige and Skoog (MS) medium supplemented with a range of concentrations of D-amino acids, except for D-Cys, significant inhibition of root and leaf development were observed, indicating that all tested D-enantiomers are toxic to Arabidopsis (see Supplemental Figure 9 online).…”

Serine racemases from barley, Hordeum vulgare L., and other plant species represent a distinct eukaryotic group: Gene cloning and recombinant protein characterization☆

“…Several D-amino acids and D-amino acid-containing peptides have been identified in plants. However, both 1a and D-alanine inhibit plant growth at low concentrations (Erikson et at., 2004), indicating that D-amino acid level should be strictly regulated in plant cells. There is no previous report on a plant D-amino acid oxidase, and the serine racemase is the only known enzyme that degrades 1a in plants.…”

d‐glufosinate as a male sterility agent for hybrid seed production

“…As far as we are aware, this is a completely novel observation. RtDAAO has previously been expressed in plants where it was used as a selectable marker for transformation (Erikson et al, 2004), but there are no reports of modified variants being used to effect conversion of D-glufosinate. To exemplify the D-glufosinate ⁄ DMRtDAAO combination as a sterility mechanism for hybrid production, we targeted DMRtDAAO to the tapetum of tobacco anthers using the TAP1 promoter from Antirrhinum majus (Nacken et al, 1991;Spena et al, 1992).…”