تاثیر گیاهان آرابیدوپسیس تراژن بیان‏ کننده آر‏ ان ‏ای ‏های کوتاه مداخله ‏گر ژن‎های پروتئین اصلی اسپرم و اندوگلوکاناز بر فعالیت Heterodera schachtii

The beet cyst nematode (BCN), Heterodera schachtii, causes serious damage and yield losses in some important crops worldwide. This study examined the efficacy of three types of transgenic Arabidopsis RNAi lines to decrease the biological activity of this devastating nematode. The first RNAi construct (E1E2-RNAi) targets two nematode endoglucanase genes, which are involved in BCN pathogenicity, the second construct (MSP-RNAi) contains a fragment corresponding to the major sperm protein transcript necessary for BCN development and reproduction, and the third construct (E1E2MSP-RNAi) comprises all three target fragments. Arabidopsis plants were transformed using floral dip. Experiments were conducted with homozygous T3 lines that carry a single copy of T-DNA. Bioassay data under in vitro aseptic cultivation indicated that feeding on these lines did not affect pathogenic activity and reproductive capacity of the initial population, whereas inoculating the progeny recovered from transgenic plants into the new MSP-RNAi and E1E2MSP-RNAi plants reduced 31-35% of the number of eggs per cyst. Moreover, the E1E2-RNAi and E1E2MSP-RNAi lines caused an 18-25% reduction in the penetration, and the male/female ratio increased more than the double. Transcript expression profiles of the target genes in all biological stages of the nematode were determined in the initial inoculated population and resulting progeny, which confirmed the suppression of the expression of these genes. In addition, reduced expression of endoglucanase genes in eggs (including a large number of unhatched larvae) and pre-parasitic J2s, originated from the initial population, showed that the effect of RNAi has been transferred to the next generation, and the progeny recovered from E1E2-RNAi and E1E2MSP-RNAi plants showed an impaired ability to infect wild-type plants.