Use of anthocyanin biosynthesis stimulatory genes as markers for the genetic transformation of haploid embryos and isolated microspores in wheat

Abstract

Experiments were undertaken to study the use of anthocyanin biosynthesis stimulatory genes under the control of CaMV35S promoter and first intron of maize alcohol dehydrogenase (Adhl), as marker genes for genetic transformation of wheat haploid embryos and microspores by microprojectile bombardment. Transient expression was monitored for isolated microspore cultures of 1 and 8 days, after bombardment at 650 and 1100 psi. Anthocyanin expression in 1 day cultured microspores was only recovered at 650 psi, while a higher expression efficiency was obtained with 8 days old microspore culture at 1100 psi. Experiments conducted on embryos show that total regeneration as well as albino and green plant regeneration of embryos were not affected by bombardment. 64.5 % embryos presented spots and 6.2 % of the regenerated plants were chimeric, with sectorial expression of anthocyanin on leaves. The comparison of GUS and anthocyanin expression was realized and we have shown that anthocyanins are more reliable markers when compared with GUS. Besides being more practical, they give a better estimation of transformation procedure efficiency. Results show that anthocyanin biosynthesis stimulatory genes should be used as markers in haploid embryos and isolated microspores transformation in wheat.