A Preliminary Study On The Function Of Arabidopsis Thaliana AT2G17350 Gene

Arabidopsis is a Brassicaceae herbaceous plant with wordwide distribution. As a model plant, the whole genome of Arabidopsis has been published. However, the function of many genes remains largely unknown. In this study, we used the reverse genetics way to investigate the biological function of the gene AT2G17350. By analyzing the relative expression in the different stress and protein levels, we speculate the possible functions of AT2G17350 and lay the foundation for further study. The main results and conclusions are as follows:1. By real-time quantitative PCR, the relative expression of AT2G17350 was preliminary investigated in different conditions. The results showed that AT2G17350 was sensitive to a variety of biological and non-biological stresses. Among them the gene has a positive response to the cold、heat and short time-dehydration treatment, AT2G17350 was also induced by exogenous hormones. These suggest that AT2G17350 is sensitive to different stresses and plays a key role in the growth and development of plants.2. Through bioinformatics analysis, we obtained four predicted proteins that may have interaction with AT2G17350. These are AT3G25980 (MAD2, a mitotic spindle checkpoint protein), AT5G65940 (CHY, a peroxidase protein which has hydrolase activity and plays an important role in fatty acid metabolism), AT4G16143 (IMPA-2, an intracellular transport protein) and AT4G02150 (IMPA-3, plays a role in proteins transport and binding, which also respond to the stress). All of these four proteins play an important role in biological processes and there is no co-expression among them. We also found that CHY, IMPA-2, IMPA-3 have more alternative splicings than that on the Tair website through cloning. For example, CHY and IMPA-2 have five additional alternative splicings, and IMPA-2 has one more.3. To study the interaction between AT2G17350 and predicted proteins, yeast two-hybrid was used. The result showed that AT2G17350 could interact with MAD2, IMPA-2 and IMPA-3. To further validate this result, prokaryotic expression was carried out. In this experiment, we found that AT2G17350 have an interaction with MAD2. Therefore, AT2G17350 might have a certain relationship in cell mitotic.4. Combined with AT2G17350’s interference, overexpression plants and the mutants of MAD2、CHY、IMPA-2、IMPA-3. Using qRT-PCR methods to illustrate the inter-relationship between the five genes. The results showed that:①these five genes were expressed in flowers, pods, leaves and rosette leaves, with higher expression in flowers and pods, suggesting they have a similar expression pattern. ②AT2G17350 was significantly induced when other genes were mutated, which is similar to compensation mechanism. ③MAD2 was significantly increased in the pods of AT2G17350’ interference and mutant homozygotes (HM) plant, while in the overexpression plant there was a significant reduction, maybe there is a antagonistic relationship between them. ④from the expression level of IMPA-2 and IMPA-3 in AT2G17350’s interference, overexpression and HM plants, that there was little relevance between IMPA-2, IMPA-3 and AT2G17350. Specific relationship among them need further studied.5. We further searched the references and got seven mitotic genes:there are MAD1, ATM, BRCA1, Bub3, cdc20, CDK and Mpsl (all mitotic checkpoint proteins, participate DNA damage response). Their expression levels in existing plants was measured and the result showed that these genes were highly expressed in AT2G17350’s interference and HM plants. This suggests that AT2G17350 might involve in DNA synthesis and replication and mitosis, thus playling an important role in biological processes.This study showed that AT2G17350 was responsed to stresses sush as different treatments and exogenous inductions, participate in the growth and development of plant. In addition, we identified that AT2G17350 could interact with MAD2, suggesting the possible function of AT2G17350 in cell mitosis. Finally, the expression of five genes in various mutants provides some evidences that AT2G17350 may have an effect in DNA damage repair. Together, these results provide a guidance and direction to futher study of AT2G17350.