Exploration Of Technology And Method For Detecting Unintended Effects Of Genetically Modified Rice With Microarray Analysis

With the development of transgenic technology, crops genetic traits improved by geneticallymanipulation will be help for agricultural production. However, the development of global transgenictechniques provides opportunities to address the questions raised by the concerns about unintendedeffects in transgenic plants，which might be harmful for agricultural production. It is generally agreedthat unintended effects should be paid particular attention in the process of safety assessment of GMcrops and their products, especially in regard to some long-term and potential food safety issues.Detection and evaluation of the unintended effects of GM plants is one of the most important contentsof the safety assessment of GM plants. Traditional methods to detect unintended effects are consideredas targeted approaches; the limitations of these methods are obvious, especially in the aspects of timeand economic consuming and lack of objectivity and impartiality. DNA microarray analysis canmeasure the individual transcript level of tens of thousands of genes simultaneously, thus providing ahigh-throughput means to analyze gene expression levels at the whole-genome scale.Transgenic rice line Huahui1(HH1) was genetically engineered to be insect-resistant throughexpressing fused insect-resistant gene of Cry1Ac/Cry1Ab by Huazhong Agricultural University, andobtained the first security certificate for genetically modified rice in China from Hubei Province in2009.However, people are still concerned about unintended effects of HH1derived from them. In our study,we perpormed DNA microarray analysis using transgenic rice line HH1and its non-transgenic controlMinghui63（MH63）to detect differentially expressed genes (DEG) and investigate unintended effects ofHH1.The experiment includes：(1) With the goal to define the distribution pattern of DEG, we performed DNA microarray analysiswith groups of HH1and MH63at different developmental stages（30d，60d，75d and90d）andenvironments（HT, LT, JxoI, Pxo99, Rs105and Xv5). The results showed that DEG, DEG of each ricechromosome and common DEG of HH1at different developmental stages and environments were allnon-uniform distributed. So we got the conclusion that DEG were non-uniformly distributed in HH1atdifferent developmental stages and/or environments.(2) In order to comprehensively investigate unintended effects of HH1, we performed DNAmicroarray analysis using HH1and MH63to detect DEG both in aerial and underground portions at30-day. The results showed that the number of DEG on chromosome10where Cry1Ab/Ac was inserted,were very small and not cause significantly unintended effects. To further explore influences of DEG onHH1, we analyzed changes in pathways of HH1using Plant MetGenMAP system. The result showedthat most of the significantly changed pathways wererelated to plant stress and defense,these changeswere possibly intended effects, because HH1were GM rice to be resistant to pest insects. The resultindicated that significantly changed pathways both in aerial and underground portions of HH1did notcause obvious unintended effects.(3) Furthermore, in order to provide further insight into understanding unintended effects in HH1 root, root characteristics parameters and root activities of MH63and HH1in different growth stageshave been detected. However, no significant difference between MH63and HH1was observed for rootcharacteristics traits and root activity. Detection of physiological indicators further clarify that there wasno obvious unintended effects in HH1root.