Wheat embryogenic callus was induced by treating immature wheat embryos with 2,4-D. Digoxigenin-labeled germin sense and anti-sense RNA probes were prepared by in vitro transcription. By using these probes it was revealed that there was a striking induction of germin gene expression prior to visible callus formation. | Turk J Biol 25 (2001) 387-396 © TÜB‹TAK In Situ Localization of Germin Gene Expression During Auxin Induced Callus Formation Mahmut ÇALIfiKAN Mustafa Kemal University, Department of Biology 31040 Hatay - TURKEY Received: Abstract: Wheat embryogenic callus was induced by treating immature wheat embryos with 2,4-D. Digoxigenin-labeled germin sense and anti-sense RNA probes were prepared by in vitro transcription. By using these probes it was revealed that there was a striking induction of germin gene expression prior to visible callus formation. Although no germin gene expression was localized on the sections of immature embryos which were not incubated in callus induction medium, following 4 hours incubation in callus induction medium, germin mRNA was localized on the sections of immature embryos. Germin gene expression more conspicuous and widespread on the sections which were incubated for 6 hours in callus induction medium. It was suggested that germin genes induced during callus formation were related to the remodeling of the cell wall to accomplish the transition from precocious germination to callus formation. Key Words: Callus, Germin, Auxin, Embryogenesis Oksin’in Oluflturdu¤u Kallus Dokusunda Germin Gen Ekspresyonunun Belirlenmesi Özet: Olgunlaflmam›fl bu¤day embriyolar› 2, 4-D ile muamele ettirilerek embriyonik kallus oluflturulmufltur. Germin’in digoxigenin ile iflaretlenmifl anlaml› ve anlams›z RNA problar› laboratuvar koflullar›nda haz›rlanm›flt›r. Bu problar kullan›larak, oksinle muameleye tabi tutulan embriyolarda, belirgin kallus oluflumundan önce önemli oranda germin gen ekspresyonunun oldu¤u anlafl›lm›flt›r. Oksinsiz ortamda bulunan embriyolarda germin gen ekspresyonu belirlenmemesine ra¤men, oksin’li ortamda 4 saatlik bir inkübasyon sonucunda embriyolarda, germin gen ekspresyonunun oldu¤u belirlenmifltir. Germin gen ekspresyonunun, oksinli ortamda 6 saatlik bir inkübasyon sonunda, çok daha yayg›n ve belirgin oldu¤u .
