پديد آورندگان :
سعيدي، عباس دانشگاه شهيد بهشتي - دانشكده علوم زيستي و بيوتكنولوژي - گروه علوم و زيست فناوري گياهي، تهران، ايران , حاجي برات، زهره دانشگاه شهيد بهشتي - دانشكده علوم زيستي و بيوتكنولوژي - گروه علوم و زيست فناوري گياهي، تهران، ايران , غفاري، محمدرضا ﺳﺎزﻣﺎن ﺗﺤﻘﯿﻘﺎت آﻣﻮزش و ﺗﺮوﯾﺞ ﮐﺸﺎورزي - ﭘﮋوﻫﺸﮕﺎه ﺑﯿﻮﺗﮑﻨﻮﻟﻮژي - بخش زﯾﺴﺖ ﺷﻨﺎﺳﯽ ﺳﯿﺴﺘﻢ ﻫﺎ، ﮐﺮج، اﯾﺮان
كليدواژه :
ﮐﺮﺑﻮﻫﯿﺪرات ﻣﺤﻠﻮل , ﺧﺸﮑﯽ , ﭘﺮﺷﺪن داﻧﻪ , ﻓﺮوﮐﺘﺎن
چكيده فارسي :
ﮔﯿﺎﻫﺎن از راﻫﺒﺮدﻫﺎي ﻣﺨﺘﻠﻔﯽ ﺑﺮاي ﻣﻘﺎﺑﻠﻪ ﺑﺎ ﺗﻨﺶﻫﺎي ﻏﯿﺮ زﯾﺴﺘﯽ اﺳﺘﻔﺎده ﻣﯽﮐﻨﻨﺪ ﮐﻪ واﺑﺴﺘﻪ ﺑﻪ ﮔﻮﻧﻪ و رﺷﺪ ﮔﯿﺎه ﻣﺘﻔﺎوت اﺳﺖ. ﯾﮑﯽ از اﯾﻦ راﻫﮑﺎرﻫﺎ اﻓﺰاﯾﺶ اﻧﺘﻘﺎل ﻣﺠﺪد ﮐﺮﺑﻮﻫﯿﺪرات ﻫﺎي ﻣﺤﻠﻮل در آب ﺳﺎﻗﻪ ﺗﺤﺖ ﺗﻨﺶ اﺳﺖ ﮐﻪ ﻣﯽﺗﻮاﻧﺪ ﺑﻪ ﻋﻨﻮان ﻣﻨﺎﺑﻊ ﻣﻬﻢ ﮐﺮﺑﻨﯽ ﺑﺮاي ﭘﺮ ﮐﺮدن داﻧﻪ در ﺑﺮاﺑﺮ ﺗﻨﺶ ﺧﺸﮑﯽ ﺑﺎﺷﻨﺪ. ﺗﻨﺶ ﺧﺸﮑﯽ ﯾﮑﯽ از ﻣﻬﻤﺘﺮﯾﻦ ﺗﻨﺶﻫﺎي ﻏﯿﺮزﯾﺴﺘﯽ اﺳﺖ ﮐﻪ ﻋﻤﻠﮑﺮد ﻣﺤﺼﻮﻻت ﮐﺸﺎورزي را ﺗﺤﺖ ﺗﺎﺛﯿﺮ ﻗﺮار ﻣﯽدﻫﺪ. ﻋﻼوه ﺑﺮ اﯾﻦ، ﺗﻨﺶ ﺧﺸﮑﯽ ﺑﻪ ﻋﻨﻮان ﯾﮑﯽ از ﻋﻮاﻣﻞ ﻣﺤﺪود ﮐﻨﻨﺪه اﺻﻠﯽ در ﻓﺮاﯾﻨﺪ رﺷﺪ ﮔﯿﺎه ﺑﻮده، ﻫﻤﭽﻨﯿﻦ ﻣﯽﺗﻮاﻧﺪ ﻣﺎﻧﻊ ﺗﻨﻔﺲ ، ﻓﺘﻮﺳﻨﺘﺰ و ﺑﺎز و ﺑﺴﺘﻪ ﺷﺪن روزﻧﻪ ﮔﯿﺎه ﺷﻮد و در ﻧﺘﯿﺠﻪ، ﺑﺮ رﺷﺪ و ﺳﻮﺧﺖ و ﺳﺎز ﻓﯿﺰﯾﻮﻟﻮژﯾﮑﯽ ﮔﯿﺎه ﺗﺄﺛﯿﺮ ﮔﺬارد. ﮔﯿﺎﻫﺎن ﺳﺎز و ﮐﺎرﻫﺎي ﭘﺎﺳﺦ ﺑﻪ ﺧﺸﮑﯽ ﻣﺎﻧﻨﺪ ﺗﻐﯿﯿﺮات ﻣﻮرﻓﻮﻟﻮژﯾﮑﯽ و ﺳﺎﺧﺘﺎري و ﻫﻤﭽﻨﯿﻦ ﺑﯿﺎن ژن ﻫﺎي ﻣﻘﺎوم ﺑﻪ ﺧﺸﮑﯽ، ﺳﻨﺘﺰ ﻫﻮرﻣﻮنﻫﺎ و ﻣﻮاد ﺗﻨﻈﯿﻢ ﮐﻨﻨﺪه اﺳﻤﺰي را ﺑﺮاي ﮐﺎﻫﺶ ﺗﻨﺶ ﺧﺸﮑﯽ ﻓﻌﺎل ﻣﯽﮐﻨﻨﺪ. ﺧﺸﮑﯽ ﺑﺎﻋﺚ ﺗﺴﺮﯾﻊ در ﭘﯿﺮي ﺑﺮگ ﻏﻼت ﺷﺪه ﮐﻪ ﺷﺎﻣﻞ ﺗﻐﯿﯿﺮات ﺑﯿﺎن ﻫﺰاران ژن ﺑﻮده و در ﻧﻬﺎﯾﺖ ﺑﺮ ﻣﯿﺰان ﭘﺮوﺗﺌﯿﻦ داﻧﻪ و ﻋﻤﻠﮑﺮد داﻧﻪ و ﮐﺎراﯾﯽ اﺳﺘﻔﺎده از ﻧﯿﺘﺮوژن ﺗﺄﺛﯿﺮ ﻣﯿﮕﺬارد. ﻫﻤﭽﻨﯿﻦ ﺗﺤﺖ اﯾﻦ ﺗﻨﺶ، ﻧﯿﺘﺮوژن ﻣﻮﺟﻮد در ﺧﺎك ﻗﺎﺑﻞ دﺳﺘﺮس ﻧﺒﻮده و ﺑﺎﻋﺚ ﺷﺮوع و ﺗﺴﺮﯾﻊ در روﻧﺪ ﭘﯿﺮي ﺑﺮگﻫﺎ ﻣﯽﺷﻮد. ﭘﯿﺮي ﺑﻪ ﺷﺪت ﺗﺤﺖ ﺗﺄﺛﯿﺮ ﻫﻮرﻣﻮنﻫﺎي ﮔﯿﺎﻫﯽ و ﻋﻮاﻣﻞ ﻣﺤﯿﻄﯽ ﺷﺎﻣﻞ در دﺳﺘﺮس ﺑﻮدن ﻧﯿﺘﺮوژن ﻣﯽﺑﺎﺷﺪ . در ﺷﺮاﯾﻂ ﺗﻨﺶ ﺧﺸﮑﯽ، ﮐﺎﻫﺶ ﺟﺬب ﻧﯿﺘﺮوژن ﻣﯽ ﺗﻮاﻧﺪ ﺑﺎﻋﺚ ﺟﺎﺑﺠﺎﯾﯽ ﻣﺠﺪد ﻧﯿﺘﺮوژن از ﺑﺮگ و ﺳﺎﻗﻪ ﺑﻪ داﻧﻪ ﺷﻮد و در ﻧﻬﺎﯾﺖ ﻣﻨﺠﺮ ﺑﻪ ﭘﯿﺮي ﺑﺮگ ﺷﻮد. در اﯾﻦ ﻣﻘﺎﻟﻪ ﻧﺸﺎن داده ﺷﺪ ﮐﻪ ژنﻫﺎي دﺧﯿﻞ در ﻣﺴﯿﺮ ﺑﯿﻮﺳﻨﺘﺰ ﻓﺮوﮐﺘﺎن، در ﺗﺠﺰﯾﻪ ﮐﻠﺮوﭘﻼﺳﺖ، در ﺗﺠﺰﯾﻪ ﭘﺮوﺗﺌﯿﻦ )ﭘﺮوﺗﺌﺎزﻫﺎ( و ﻓﺎﮐﺘﻮرﻫﺎي روﻧﻮﯾﺴﯽ )WRKY ،NAC( در روﻧﺪ ﭘﯿﺮي ﺳﻠﻮل اﻓﺰاﯾﺶ ﺑﯿﺎن ﻧﺸﺎن ﻣﯽدﻫﻨﺪ.
چكيده لاتين :
Plants utilize different strategies to combat abiotic stress, depending on the species and growth stage. One of these strategies is to increase the remobilization of water-soluble carbohydrates (WSC) under stress, which can be important sources of carbon to fill the grain in response to drought stress. Drought is one of the most important abiotic stresses affecting yield of agricultural products. In addition, drought stress is one of the main limiting factors in plant growth, it can also prevent respiration, photosynthesis and opening and closing of plant stomata. As a result, it affects the growth and physiological metabolism of the plant. In response to drought stress, plants activate drought response mechanisms such as morphological and structural changes as well as the expression of responsive-drought genes, the synthesis of hormones and osmotic regulators to reduce drought stress. Drought initiates the senescence of cereal leaves, including changes in the expression of thousands of genes that ultimately affect grain protein content, grain yield, and nitrogen utilization efficiency. Also, under drought stress, soil nitrogen availability is reduced causing initiation and acceleration of the leaves senescence. Leaf senescence is strongly influenced by plant hormones and environmental factors including the availability of nitrogen. During maturity or drought stress, reduced nitrogen uptake can cause nitrogen to be redistributed from leaves and stems to seeds, eventually leading to leaf senescence. Under these conditions, genes involved in the fructan biosynthesis pathway and in chloroplast degradation and proteases show increased expression. For example, genes involved in protein degradation (proteases) and transcription factors (NAC, WRKY) are expressed in the process of cells senescence. In this paper, it was shown that the genes involved in the fructan biosynthesis pathway, chloroplast degradation, protein degradation (proteases), and transcription factors (NAC, WRKY) during the aging process show increased expression.
