15140

13617

كارشناسي ارشد

بيوتكنولوژي كشاورزي

اصفهان : دانشگاه صنعتي اصفهان

1398

هشت، 130 ص.: مصور، جدول،‌نمودار.

آذر شاه پيري

پوراندخت گلكار، آقافخر ميرلوحي

ابوذر سورني، امير مساح

1398/07/02

كتابنامه

كشاورزي

مهندسي كشاورزي

1398/07/14

2561851

expression analysis of metallothionein genes MT4 and MT2b2 involved in Zn accumulation in the barley aleurone layer in response to hormones Zahra Pourjalali Zahra pourjalali@yahoo com July 3 2019 Department of Agricultural Biotechnology Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc language farsi Supervisor Azar Shahpiri a shahpiri@cc iut ac irAbstractZinc is a trace mineral essential to all life forms due to its key role in gene expression cell developmentand replication In humans zinc is an essential cofactor for more than 300 different enzymes The onlyway to absorb zinc in humans is through diet Cereals are staple food of people in developing countries However in cereals the presence of inhibitors like phytic acid impedes bioavailability of zinc In additionthe zinc deposited in the husk and embryo typically 50 of the total zinc in the grain of cereal seeds isremoved during milling and polishing which resulted in remaining of low amount of zinc in endospermfraction Therefore zinc biofortification of edible crops is necessary Many genes such asmetallothioneins MTs are involved in control the distribution of various metals throughout the plant Based on the previous reports it seems that two MT genes MT4 and MT2b2 are involved in accumulationof zinc in aleurone layer and embryo therefore the in the present research expression analysis of thesegenes were monitored in dissected aleurone layers from barley Hordeum vulgare seeds incubated for 24hours in the presence of the hormones gibberellic acid GA abscisic acid ABA salicylic acid SA indole 3 acetic acid IAA kinetin K and ethephon Et The aleurone layers were also treated with acombination of hormones GA ABA and GA SA Then RNA in the aleurone was extracted using SDS based method and the cDNA was synthesized Appropriate annealing temperature of designed specificprimer pairs were determined by gradient PCR and expression of genes was evaluated by Real Time PCRreaction The results show that some hormones up regulated the expression of MT4 and MT2b2 in thealeurone An outstanding increase in the expression of these genes was observed in response to SA Based on the recent works the protein MT4 was known as a protein with specific ability for binding tozinc This isoform was not able to bind to other metals like cadmium Nevertheless there was not anyinformation about the metal binding function of MT2b2 Therefore in this study the gene encodingMT2B2 was amplified by RT PCR and cloned in the expression vector pET41a The new constructpET41a MT2b2 was transformed to Ecoli strain Rosetta DE3 Following the induction with IPTG theMT2b2 was expressed as glutathione S transferase GST tagged fusion protein In comparison tocontrol strain the cells expressing MT2b2 was more tolerant in the medium containing toxicconcentration of zinc and was able to accumulate Zn2 In comparison this strain was not able toaccumulate cadmium which may suggest that MT2b2 is specific chelators for zinc and could be a goodcandidate for zinc accumulation in barley seeds Key words Zinc Metallothionein Biofortification Real Time PCR Aleurone layer 434

آذر شاه پيري

پوراندخت گلكار، آقافخر ميرلوحي

ابوذر سورني، امير مساح