Study On Gene Differential Expression Of The Interaction Between Sugarcane And Smut Caused By U.stilago Scitaminea Syd

Sugarcane Ustilago Scitaminea Syd(Smut), caused by Ustilago Scitaminea Syd, is an worldwide severe disease of sugarcane(interspecific Saccharum hybrids). Because of the severe economic losses in Smut epidemics, many sugarcane-producing countries had to eliminate some of the high yeild, high sugar content, however susceptible trade cultivars. So the breeding of Smut-resistant sugarcane cultivars is a crucial key topic in both inheritance and breeding of sugarcane and production practice. This study selected sugarcanes of different resistance types to detect the difference of gene expression before and after they were infeced by Ustilago Scitaminea Syd, thus affords molecular basis for sugarcane's Smut-resistant breeding. The high-resistance sugarcane cultivar "NC0376" and the high-sensitivity one "F134" were selected as experimental host material to be treated with Ustilago Scitaminea Syd and the healthy lines treated with distilled water were selected as control respectively. Ninty-six primer pairs obtained by random constitution between twelve 3' anchored primers and eight 5' random primers were utilized and DDRT-PCR(differential display retrotranscriptation-PCR) was exploited to achieve high efficent screen for differentially expressed gene. The results showed that differentially expressed bands could be amplified with twenty of the ninty-six primer pairs. Among the twenty, the most effective random primers wereARP2, ARP4, ARP11, with which differential bands were able to be detected in combination with three anchored primers AP2,AP7 and AP8; the most effective anchored primers were AP2 and AP7 ended by CGs or GCs . Eleven differentially expressed bands were screened altogether, of which four were expressed in infected NC0376 while not detectable in the control, indicating the expression of some gene increased in infected NC0376; Six bands appeared in infected F134, One were expressed in the control, suggesting one gene had silenced in the infected cultivar. Subsequently the collected bands'were cloned and sequenced, and homology blast were conducted through Genbank for them. Results showed that one cDNA segment expressed only in infected NC0376(RIl)was 100% homologous to gene of cytochrome c oxidase from maize, durra> and wheat; six were highlyhomologous to tnRNA sequences from maize or wheat; the remaining three had no any homology to the exsiting sequences in Genbank, suggesting that these three might be parts of new gene segments. Results of semi-quantitative RT-PCR on sequence of RI1, RI2, RI3, RI4, S01 verified that the sequences of RI1, RI2, RI3 were positive and those of SOI, RI4 were false positive.