Viljelusviisi mõju nisu lämmastiku omastamise eest vastutavate geenide ekspressioonile
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Kuupäev
2017
Kättesaadavus
Autorid
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Eesti Maaülikool
Abstrakt
Eesti nisusaagid jäävad Kesk-Euroopa saakidele alla ning maheviljeluses on saagikused
veelgi madalamad. Teravilja saagikust mõjutab kaks põhilist komponenti: fotosünteetiline
potensiaal ja toitainetega varustatus. Teades põhilisi lämmastiku omastamise ja kasutamise
eest vastutavaid geene ning teades nende toimemehhanisme, on võimalik taimede saagikusi
oluliselt tõsta ning samal ajal lämmastikväetiste koguseid alandada. Nisus on iseloomustatud
lämmastikuühendite transpordi eest vastutavad NRT, AMT transportereid ning lämmastiku
kasutamist reguleerivad nitraadi reduktaas, glutamiini süntetaas ning glutamaadi süntaas.
Uurimistöö eesmärk oli anda põhjalik ülevaade lämmastiku omastamise eest vastutavatest
geenidest ning töötada välja metoodika nende transkirptsionaalse aktiivsuse määramiseks.
Väljatöötatud metoodikat testiti NRT1 geeni ekspressiooni analüüsimisega.
Lämmastiku vorm ehk viljelusviis ei avaldanud mõju NRT1 ekspressioonitasemele nisu
lehtedes ega ka juurtes. See-eest lämmastiku eri normide puhul oli NRT1 ekspressioon
juurtes kõrgemate lämmastiku foonide puhul madalam.
Väljatöötatud ja testitud protokolli abil saab analüüsida kõikide põhiliste nisu lämmastiku
omastamise eest vastutavate geenide ekspressioonitaset ning anda täielikum hinnang
viljelusviisi mõjust geeniekspressioonile. See omakorda aitab välja selgitada saagikuse
erinevuste taga olevat mehhanismi.
Estonian wheat yields are not up to the competition with the Central-European yields. Organic farming yields are approximately 25% lower compared to the conventional farming. The yield of cereals depends on two main factors: photosynthetic potential and the availability of nutrients. The knowledge about the main genes responsible for nitrogen aquisiton and use can be used to significantly increase the yields while decreasing the need for nitrogen fertilizers. There are several genes in wheat responsible for nitrogen assimilation and uptake. NRT and AMT transporters are responsible for nitrogen transport. Nitrate reductase, glutamine synthase and glutamate synthetase are regulating the use of nitrogen. The aim of the research was to give a thorough overview of the wheat genes related to nitrogen use and to develop and test a protocol to study the transcriptional activity of these genes in different farming systems. The protocol was tested on analysing NRT1 gene expression. Farming system had no statistically significant impact on NRT1 expression in wheat leaves or roots. However, the higher nitrogen rates decreased the NRT1 expression in roots. The newly developed protocol will be used to test all the genes responsible for nitrogen acquisition to characterize the impact of farming system on those genes. This in turn will help to explain the mechanism behind the yield gap.
Estonian wheat yields are not up to the competition with the Central-European yields. Organic farming yields are approximately 25% lower compared to the conventional farming. The yield of cereals depends on two main factors: photosynthetic potential and the availability of nutrients. The knowledge about the main genes responsible for nitrogen aquisiton and use can be used to significantly increase the yields while decreasing the need for nitrogen fertilizers. There are several genes in wheat responsible for nitrogen assimilation and uptake. NRT and AMT transporters are responsible for nitrogen transport. Nitrate reductase, glutamine synthase and glutamate synthetase are regulating the use of nitrogen. The aim of the research was to give a thorough overview of the wheat genes related to nitrogen use and to develop and test a protocol to study the transcriptional activity of these genes in different farming systems. The protocol was tested on analysing NRT1 gene expression. Farming system had no statistically significant impact on NRT1 expression in wheat leaves or roots. However, the higher nitrogen rates decreased the NRT1 expression in roots. The newly developed protocol will be used to test all the genes responsible for nitrogen acquisition to characterize the impact of farming system on those genes. This in turn will help to explain the mechanism behind the yield gap.
Kirjeldus
Magistritöö
Põllumajandussaaduste tootmise ja turustamise õppekaval
Märksõnad
magistritööd, maheviljelus, tavaviljelus, nisu, lämmastik, geeniekspressioon