بررسي بيان ژن NHX در گياه گندم (T. aestivum) در شرايط تنش شوري توسط RT-PCR

Investigation of NHX Gene Expression to Salinity stress in wheat (T. aestivum) by RT-PCR

ﺑﻪ دﻟﯿﻞ ﻣﻘﺎوﻣﺖ ﺑﺎﻻي ﮔﻨﺪم در ﻣﻘﺎﺑﻞ ﺗﻨﺶ ﻫﺎي ﻣﺤﯿﻄﯽ، ﻣﯽ ﺗﻮان از آن ﺑﻪ ﻋﻨﻮان ﮔﯿﺎه ﻣﺪل ﺟﻬﺖ ﻣﻄﺎﻟﻌﻪ اﺳﺎس ﻣﻮﻟﮑﻮﻟﯽ ﺗﺤﻤﻞ ﺑﻪ ﺗﻨﺶ ﻫﺎ اﺳﺘﻔﺎده ﻧﻤﻮد. در ﮔﯿﺎﻫﺎن ﯾﮏ ﻣﮑﺎﻧﯿﺰم ﻋﻤﺪه در ﺗﺮاﺑﺮي +Na ﺳﯿﺘﻮﺳﻮﻟﯽ و ﮐﺎﻫﺶ اﺛﺮات ﺳﻤﯽ آن وﺟﻮد دارد ﮐﻪ ﺑﺎﻋﺚ ﺟﺎﯾﮕﺬاري ﻣﻘﺎدﯾﺮ اﺿﺎﻓﯽ ﯾﻮن ﻫﺎي ﺳﺪﯾﻢ در واﮐﻮﺋﻞ ﻫﺎ ﯾﺎ ﺑﺎﻓﺖ ﻫﺎﯾﯽ ﺑﺎ ﺣﺴﺎﺳﯿﺖ ﮐﻤﺘﺮ ﻣﯽ ﺷﻮد ﮐﻪ اﯾﻦ ﮐﺎر ﺗﻮﺳﻂ آﻧﺘﯽ ﭘﻮرﺗﺮ ﻏﺸﺎي واﮐﻮﺋﻠﯽ )NHX( ﺻﻮرت ﻣﯽ ﮔﯿﺮد در اﯾﻦ ﺗﺤﻘﯿﻖ اﻟﮕﻮي ﺑﯿﺎن ژن NHX در ﮔﯿﺎه ﮔﻨﺪم ﺗﺤﺖ ﺗﻨﺶ ﺷﻮري ﺑﺎ اﺳﺘﻔﺎده از روش -RT PCR ﻧﯿﻤﻪ ﮐﻤﯽ ﻣﻮردﺑﺮرﺳﯽ ﻗﺮار ﮔﺮﻓﺖ. ﺑﺪﯾﻦ ﻣﻨﻈﻮر ﮔﯿﺎﻫﭽﻪﻫﺎي 12 روزه ﺑﺎ ﻏﻠﻈﺖ ﻫﺎي 0 ، 50 ، 100 ، 150 و 200 ﻣﯿﻠﯽ ﻣﻮﻻر ﮐﻠﺮﯾﺪ ﺳﺪﯾﻢ ﻣﻮرد ﺗﯿﻤﺎر ﻗﺮار ﮔﺮﻓﺘﻨ.ﺪ ﻧﻤﻮﻧﻪ ﺑﺮداري از ﮔﯿﺎﻫﺎن ﺷﺎﻫﺪ و ﺗﯿﻤﺎر ﺷﺪه 6، 12، 24و 48 ﺳﺎﻋﺖ ﭘﺲ از اﻋﻤﺎل ﺗﻨﺶ ﺻﻮرت ﮔﺮﻓﺖ. ﻧﺘﺎﯾﺞ ﺣﺎﺻﻞ از آﻧﺎﻟﯿﺰ ﻣﻮﻟﮑﻮﻟﯽ ﻧﺸﺎن داد ﮐﻪ ﻣﯿﺰان ﺑﯿﺎن ژن NHX در ﺗﻤﺎم ﻏﻠﻈﺖ ﻫﺎي ﺑﺮرﺳﯽ ﺷﺪه ﻧﻮﺷﺘﻪ ﺷﻮد. در ﮔﯿﺎﻫﺎن ﺗﺤﺖ ﺗﻨﺶ ﻧﺴﺒﺖ ﺑﻪ ﮔﯿﺎه ﺷﺎﻫﺪ اﻓﺰاﯾﺶ ﻗﺎﺑﻞ ﺗﻮﺟﻬﯽ ﻧﺸﺎن داد. ﺣﺪاﮐﺜﺮ ﻣﯿﺰان ﺑﯿﺎن ژن در ﺳﺎﻋﺎت ﻣﺨﺘﻠﻒ در ﻏﻠﻈﺖ 150 ﻣﯿﻠﯽ ﻣﻮﻻر ﮐﻠﺮﯾﺪ ﺳﺪﯾﻢ ﻣﺸﺎﻫﺪه ﮔﺮدﯾ.ﺪ ﻧﺘﺎﯾﺞ ﮐﻠﯽ ﻧﺸﺎن دﻫﻨﺪه ﻧﻘﺶ ژن ﮐﺪ ﮐﻨﻨﺪه آﻧﺘﯽ ﭘﻮرﺗﺮ ﻏﺸﺎ واﮐﻮﺋﻠﯽ در ﭘﺎﺳﺦ ﮔﯿﺎه ﮔﻨﺪم ﻧﺴﺒﺖ ﺑﻪ ﺗﻨﺶ ﺷﻮري ﻣﯽ ﺑﺎﺷﺪ.

Wheat is a grass widely cultivated for its seed, a cereal grain which is a worldwide staple food. The many species of wheat together make up the genus Triticum. the most widely grown is common wheat (T. aestivum). There is a major mechanism in the plants to transfer cytosol Na+reducing its toxic effects. In this mechanism the excess of Na+ was pumped in the vacuoles or tissues with less sensitive. This displacement was carried by vacuole antiporter (NHX). In this study, the pattern of NHX expression was studied in T. aestivum under salt stress by using semiquantitative RT-PCR. In this experiment,15-days-old plants of resistant variety of T. aestivum, PBR-321, were subjected to NaCl treatment (with five concentrations of 50, 100, 150 and 200mM). Sampling of control and treated plants were performed at different time points (6, 12, 24 and 48 hours) after all four salt treatments. The results showed that expression rate of NHX gene increased in all concentrations at different times than control plant. Maximum expression levels at different times were observed in 200mM of Sodium chloride. Totally, NHX antiporterhas important role in response to salt stress is T. aestivum.