ارزيابي آثار غلظت و زمان كاربرد نانو اكسيد گرافن بر عملكرد فتوسنتزي و آنتي اكسيداني خيار در شرايط گلخانه اي

Evaluation of concentration and application time of Nanographene oxide on photosynthetic and antioxidant performance of cucumber in greenhouse conditions

زﻧﺪﮔﯽ ﮔﯿﺎﻫﺎن ﻣﺘﺄﺛﺮ از ﭼﺮﺧﻪ ﮐﺮﺑﻦ ﺑﻮده و ﮐﺸﻒ اﺷﮑﺎل ﺟﺪﯾﺪ ﮐﺮﺑﻦ در ﺳﺎلﻫﺎي اﺧﯿﺮ اﯾﻦ ﺳﺆال را ﭘﺪﯾﺪ آورده اﺳﺖ ﮐﻪ اﯾﻦ اﺷﮑﺎل ﭼﻪ ﺗﺄﺛﯿﺮي ﺑﺮ ﮔﯿﺎﻫﺎن دارﻧﺪ. ﯾﮑﯽ از اﯾﻦ اﺷﮑﺎل ﺟﺪﯾﺪ،ﮔﺮاﻓﻦ اﺳﺖ ﮐﻪ ﻓﺮم ﻧﺎﻧﻮي آن در اﺛﺮ ﺷﮑﺴﺖ ﻣﮑﺎﻧﯿﮑﯽ ﻣﻮاد ﮔﺮاﻓﯿﺘﯽ اﯾﺠﺎد ﻣﯽﺷﻮد. در اﯾﻦ ﻣﻄﺎﻟﻌﻪ، ﺗﺄﺛﯿﺮ ﻏﻠﻈﺖﻫﺎي ﻣﺨﺘﻠﻒ ﻧﺎﻧﻮ اﮐﺴﯿﺪ ﮔﺮاﻓﻦ ﺑﺮ رﺷﺪ، ﻣﯿﺰان ﻓﺘﻮﺳﻨﺘﺰ و ﻓﻌﺎﻟﯿﺖ آﻧﺰﯾﻢﻫﺎي آﻧﺘﯽاﮐﺴﯿﺪاﻧﯽ ﮔﯿﺎه ﺧﯿﺎر ﮔﻠﺨﺎﻧﻪاي در ﻣﺤﯿﻂﮐﺸﺖ ﻫﯿﺪروﭘﻮﻧﯿﮏ ﺑﺮرﺳﯽ ﺷﺪ. رﯾﺸﻪ ﮔﯿﺎهﭼﻪﻫﺎ ﻗﺒﻞ از اﻧﺘﻘﺎل ﺑﻪ ﻣﺤﯿﻂﮐﺸﺖ ﺑﻪ ﻣﺪت 30 و 60 دﻗﯿﻘﻪ در ﻣﺤﻠﻮلﻫﺎﯾﯽ ﺑﺎ ﻏﻠﻈﺖ 1/6 ،1/2 ،0/8 ،0/4 و 2 ﻣﯿﻠﯽﮔﺮم ﺑﺮ ﻣﯿﻠﯽﻟﯿﺘﺮ ﻧﺎﻧﻮ اﮐﺴﯿﺪ ﮔﺮاﻓﻦ ﻗﺮار ﮔﺮﻓﺘﻨﺪ. ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد ﮐﻪ ﻧﺎﻧﻮ اﮐﺴﯿﺪ ﮔﺮاﻓﻦ در ﻏﻠﻈﺖﻫﺎي ﮐﻢ )1/2 ﻣﯿﻠﯽﮔﺮم ﺑﺮ ﻣﯿﻠﯽﻟﯿﺘﺮ( ﻣﯽﺗﻮاﻧﺪ ﺑﺎﻋﺚ اﻓﺰاﯾﺶ وزن ﺗﺮ و ﺧﺸﮏ رﯾﺸﻪ و اﻧﺪام ﻫﻮاﯾﯽ، ﻣﯿﺰان ﮐﻠﺮوﻓﯿﻞ و ﺑﺎزده ﺑﯿﺸﯿﻨﻪ ﻓﺘﻮﺳﻨﺘﺰي ﺷﻮد. ﺑﯿﺸﯿﻨﻪ ﻣﯿﺰان ﮐﻠﺮوﻓﯿﻞ )41/18( و ﺑﺎزده ﺑﯿﺸﯿﻨﻪ ﻓﺘﻮﺳﻨﺘﺰي )0/42( در ﻏﻠﻈﺖ 1/2 ﻣﯿﻠﯽﮔﺮم ﺑﺮ ﻣﯿﻠﯽﻟﯿﺘﺮ ﻣﺸﺎﻫﺪه ﺷﺪ. ﺑﯿﺸﺘﺮﯾﻦ ﻓﻌﺎﻟﯿﺖ آﻧﺰﯾﻢﻫﺎي ﭘﺮاﮐﺴﯿﺪاز و ﺳﻮﭘﺮاﮐﺴﯿﺪ دﺳﻤﻮﺗﺎز ﺑﻪﺗﺮﺗﯿﺐ در ﻏﻠﻈﺖﻫﺎي 1/2 و 1/6 ﻣﯿﻠﯽﮔﺮم ﺑﺮ ﻣﯿﻠﯽﻟﯿﺘﺮ ﻣﺸﺎﻫﺪه ﺷﺪ. ﻣﯿﺰان ﻏﻠﻈﺖ ﻣﺎﻟﻮنديآﻟﺪﺋﯿﺪ ﻧﯿﺰ در ﻏﻠﻈﺖ 1/2 ﻣﯿﻠﯽﮔﺮم ﺑﺮ ﻣﯿﻠﯽﻟﯿﺘﺮ 58 )در زﻣﺎن 30 دﻗﯿﻘﻪ( و 23 )در زﻣﺎن 60 دﻗﯿﻘﻪ( درﺻﺪ ﻧﺴﺒﺖ ﺑﻪ ﺷﺎﻫﺪ ﮐﺎﻫﺶ ﭘﯿﺪا ﮐﺮد. ﻫﻤﭽﻨﯿﻦ، ﻧﺎﻧﻮ اﮐﺴﯿﺪ ﮔﺮاﻓﻦ ﺑﺎﻋﺚ اﻓﺰاﯾﺶ ﻏﻠﻈﺖ ﻋﻨﺎﺻﺮ ﻧﯿﺘﺮوژن، ﭘﺘﺎﺳﯿﻢ و آﻫﻦ و ﮐﺎﻫﺶ ﻏﻠﻈﺖ ﮐﻠﺴﯿﻢ ﻧﺴﺒﺖ ﺑﻪ ﺗﯿﻤﺎر ﺷﺎﻫﺪ ﺷﺪ، اﻣﺎ ﺗﻔﺎوت ﻣﻌﻨﯽداري در ﻏﻠﻈﺖ ﻓﺴﻔﺮ و روي ﻣﺸﺎﻫﺪه ﻧﺸﺪ. ﺑﺎﺗﻮﺟﻪﺑﻪ ﻧﺘﺎﯾﺞ ﺣﺎﺻﻞ ﺑﻪ ﻧﻈﺮ ﻣﯽرﺳﺪ از ﻏﻠﻈﺖﻫﺎي ﺑﻬﯿﻨﻪ ﻧﺎﻧﻮ اﮐﺴﯿﺪ ﮔﺮاﻓﻦ ﻣﯽﺗﻮان ﺑﻪﻋﻨﻮان ﺗﻨﻈﯿﻢﮐﻨﻨﺪه و ﻣﺤﺮك رﺷﺪ ﮔﯿﺎه ﺧﯿﺎر اﺳﺘﻔﺎده ﮐﺮد.

Plant’s life has been affected by the carbon cycle. The discovery of new forms of carbon in recent years has raised the question of how these forms affect the plants. One of these new forms of graphene is the nanosized form caused by the mechanical breakdown of graphite materials. In this study, the effect of different concentrations of nanographene oxide (NGO) on plant growth, photosynthesis and antioxidant enzymes activity of cucumber plants in the hydroponic culture were investigated. The seedlings root were treated with different concentrations of NGO including 0.4, 0.8, 1.2, 1.6 and 2 mg.ml-1 graphene oxide for 30 and 60 minutes before transferring to a culture medium. The results showed that NGO at lower concentrations (1.2 mg.ml-1) can increase plant growth characteristics such as root and shoot dry weight as well as an increase in chlorophyll content and maximum photosynthetic yield. Maximum chlorophyll content (41.18) and photosynthetic efficiency (0.42) were observed at 1.2 mg.ml-1. The maximum activity of peroxidase and superoxide dismutase enzymes was observed at concentrations of 1.2 and 1.6 mg.ml-1 respectively. Malondialdehyde content decreased by %58 (in 30 min) and %23 (in 60 min) at 1.2 mg.ml-1 concentration compared to control. The NGO also increased the concentration of nitrogen, potassium and iron and decreased the concentration of calcium compared to the control, but no significant difference was observed in the concentration of phosphorus and zinc. In fact, optimal concentrations of NGO can be used as a regulator and stimulant of cucumber plants growth. However, further studies are needed to investigate the effect of these emerging nanoparticles on plants.