Analysis Of Atcesas Expression Under Pathogen Infection In Arabidopsis

Lignocellulose-based bioenergy is considered as an ideal renewable energy. But because of a low efficient degradation, its application can not yet be available for industrialization purpose. Thus, understanding of cellulose synthesis is scientifically important. In Arabidopsis, ten cellulose synthase genes (AtCesAs) have been identified. Among them, AtCesA1, AtCesA3 and AtCesA6 are involved in the primary cell wall synthesis, whereas AtCesA4, AtCesA7 and AtCesA8 are associated with secondary cell wall synthesis. It is not very clear about functions of AtCesA2, AtCesA5, AtCesA9 and AtCesA10. Here, I used GUS as the reporter gene to observe the expression patterns of AtCesAs under the pathogen infection conditions. Then, I attempted to discuss their functions in cell wall biosynthesis. The main results are as follows:1. AtCesA1, AtCesA2, AtCesA3 and AtCesA6 are expressed in the same period and tissues. They expressed in the stages of root, stem, leaf, flower and pod, which is consistent with previous report that four genes are involved in the primary wall synthesis. AtCesA4, AtCesA7 and AtCesA8 are extremely highly expressed in the veins and flowers, which supports that they are associated with the second wall synthesis. AtCesA5 shows the same expression as AtCesAl, AtCesA3, AtCesA6 in the vegetative growth stage. During the flower stage, AtCesA5 are expressed in all organs except flower. And in the pod stage, AtCesA5 can not be detected at any tissues, suggesting its involvement in the primary wall synthesis. AtCesA9 is expressed in the meristem and flowers, but AtCesA10 can not be detected in any tissues.2. Erwinia carotovora ssp. Carotovora is bacteria. Inoculated with the bacteria for 6-8h, Arabidopsis leaves had 25% tissues infected. Real Time-PCR showed that the expression of most genes can reach the maximum at this time. GUS staining showed that AtCesA1, AtCesA3 and AtCesA6 were strongly expressed around the infected areas. Under this condition, AtCesA2 showed a similar expression patter to AtCesA1, AtCesA3 and AtCesA6, whereas AtCesA5, like AtCesA4, AtCesA7 and AtCesA8, was not much changed at transcript level. With the same infection, AtCesA6 expression was not increased in the prc1-1, one mutant of AtCesA6. 3. Sclerotinia sclerotiorum (Lib.) de Bary are fungal pathogens. Inoculated with the fungal for 6-8h, Arabidopsis leaves had 25% tissues infected. GUS staining shows that AtCesAl, AtCesA3 and AtCesA6 are strongly expressed around the infected tissues. AtCesA2 expression is similar to above primary wall genes, whereas AtCesA5 expression is similar to the secondary wall genes (AtCesA4, AtCesA7 and AtCesA8). But, Real time PCR indicated that AtCesA5 expression was lightly decreased whereas other genes were increased.4. Arabidopsis CesAs showed a similar expression pattern under both Ecc and Sclerotinia sclerotiorum (Lib.) de Bary infection, but expression level was a little higher with fungal treatment.5. There is no big change between prc1-1 and WT when they were infected.