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ARS Home » Plains Area » Lubbock, Texas » Cropping Systems Research Laboratory » Plant Stress and Germplasm Development Research » Research » Publications at this Location » Publication #325076
Title: Leaf proteome characterization in the context of physiological and morphological changes in response to copper stress in sorghum

Author
item ROY, SWAPAN KUMAR - Chungbuk National University
item CHO, SEONG-WOO - Chungbuk National University
item KWON, SOO JEONG - Chungbuk National University
item KAMAL, ABU HENA - University Of Texas
item KIM, SANG-WOO - Chungbuk National University
item OH, MYEONG-WON - National Academy Of Agricultural Science
item SARKER, KABITA - Chungbuk National University
item LEE, MOON-SOON - Chungbuk National University
item CHUNG, KEUN-YOOK - Chungbuk National University
item Xin, Zhanguo
item WOO, SUN-HEE - Chungbuk National University

Submitted to: Biometals
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/3/2016
Publication Date: 6/1/2016
Citation: Roy, S., Cho, S., Kwon, S., Kamal, A., Kim, S., Oh, M., Sarker, K., Lee, M., Chung, K., Xin, Z., Woo, S. 2016. Leaf proteome characterization in the context of physiological and morphological changes in response to copper stress in sorghum. BioMetals. 29(3):495-513.

Interpretive Summary: Heavy metals are among the most widespread soil contaminants, and they can cause damage to plants by inducing alterations in major physiological and metabolic processes. The effects of certain heavy metals, such as cadmium (Cd), copper (Cu), lead (Pb) and zinc (Zn), have become an important concern for plant scientists because of their harmful effects on soil plant and other cellular systems in the environment. Copper (Cu) is an essential micronutrient required for the growth and development of plants. However, at elevated concentrations in soil, copper is very toxic to plant cells due to its inhibitory effects against many physiological and biochemical processes. In spite of its potential physiological and economical significance, molecular characterization after Cu stress has so far been grossly overlooked in sorghum. To explore the molecular alterations that occur in response to copper stress, the present study was executed in ten-day-old Cu-exposed leaves of sorghum seedlings. The growth of shoots was markedly reduced, and ionic alterations were prominently observed in the leaves when the seedlings were exposed to different concentrations (0, 100, and 150 µM) of CuSO4. Using two-dimensional gels with silver staining, 643 differentially expressed protein spots (= 1.5-fold) were identified as either significantly increased or reduced in abundance using Progenesis SameSpot software. Of these spots, a total of 24 protein spots (= 1.5-fold) from Cu-exposed sorghum leaves were successfully analyzed by MALDI-TOF-TOF mass spectrometry. Of the 24 differentially expressed proteins from Cu-exposed sorghum leaves, a total of 13 proteins were up-regulated, and 11 proteins were down-regulated. The abundance of most identified protein species, which function in carbohydrate metabolism, stress defense and protein translation, was significantly enhanced, while that of another protein species involved in energy metabolism, photosynthesis and growth and development were severely reduced. In addition, the up-regulation of glyceraldehyde-3-phosphate dehydrogenase may play an important role in Cu-related toxicity and stress responses. The resulting differences in protein expression patterns together with related morpho-physiological processes suggested that these results could help to elucidate plant adaptation to Cu stress and provide insights into the molecular mechanisms of Cu responses in C4 plants.

Technical Abstract: Copper (Cu) is an essential micronutrient required for the growth and development of plants. However, at elevated concentrations in soil, copper is very toxic to plant cells due to its inhibitory effects against many physiological and biochemical processes. In spite of its potential physiological and economical significance, molecular characterization after Cu stress has so far been grossly overlooked in sorghum. To explore the molecular alterations that occur in response to copper stress, the present study was executed in ten-day-old Cu-exposed leaves of sorghum seedlings. The growth of shoots was markedly reduced, and ionic alterations were prominently observed in the leaves when the seedlings were exposed to different concentrations (0, 100, and 150 µM) of CuSO4. Using two-dimensional gels with silver staining, 643 differentially expressed protein spots (= 1.5-fold) were identified as either significantly increased or reduced in abundance using Progenesis SameSpot software. Of these spots, a total of 24 protein spots (= 1.5-fold) from Cu-exposed sorghum leaves were successfully analyzed by MALDI-TOF-TOF mass spectrometry. Of the 24 differentially expressed proteins from Cu-exposed sorghum leaves, a total of 13 proteins were up-regulated, and 11 proteins were down-regulated. The abundance of most identified protein species, which function in carbohydrate metabolism, stress defense and protein translation, was significantly enhanced, while that of another protein species involved in energy metabolism, photosynthesis and growth and development were severely reduced. In addition, the up-regulation of glyceraldehyde-3-phosphate dehydrogenase may play an important role in Cu-related toxicity and stress responses. The resulting differences in protein expression patterns together with related morpho-physiological processes suggested that these results could help to elucidate plant adaptation to Cu stress and provide insights into the molecular mechanisms of Cu responses in C4 plants.