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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 #339271

Research Project: Genetic Enhancement of Sorghum as a Versatile Crop

Location: Plant Stress and Germplasm Development Research

Title: Proteome characterization of copper stress responses in the roots of 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 MOSTAF - University Of Texas
item SARKER, KABITA - Chungbuk National University
item LEE, DONG-GI - Chungbuk National University
item Xin, Zhanguo
item WOO, SUN-HEE - Chungbuk National University

Submitted to: Biometals
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/18/2017
Publication Date: 9/21/2017
Citation: Roy, S., Cho, S., Kwon, S., Kamal, A., Sarker, K., Lee, D., Xin, Z., Woo, S. 2017. Proteome characterization of copper stress responses in the roots of sorghum. Biometals. 30(5):765-785. 10.1007/s10534-017-0045-7.
DOI: https://doi.org/10.1007/s10534-017-0045-7

Interpretive Summary: Sorghum (Sorghum bicolor L. Moench) is versatile crop resilient to multiple abiotic stresses and provides staple food for millions of people in Africa and Southeast Asia. Copper (Cu) is an essential micronutrient for all living organisms, but at elevated concentrations, it is extremely toxic to plants and can inactivate and disturb protein structures. In this report, we studied the effect of Cu, in the form of CuSO4, on sorghum roots. Seedlings of sorghum inbred line BTx623 were exposed to different concentrations (0, 50, and 100 µM) of CuSO4. Root growth was severely inhibited at both 50 and 100 µM of Cu2+. To understand the molecular mechanisms of Cu toxicity, we used proteome analysis, high-throughput two-dimensional polyacrylamide gel electrophoresis coupled with MALDI-TOF-TOF mass spectrometry to examine the changes of protein profile in Cu-treated sorghum roots. In two-dimensional silver-stained gels, a total of 422 differentially expressed proteins (= 1.5-fold) were identified using Progenesis SameSpot software. A total of 21 protein spots (= 1.5-fold) from Cu-induced sorghum roots were analyzed by mass spectrometry. Of the 21 differentially expressed protein spots from Cu-induced sorghum roots, a total of 10 proteins were up-regulated and 11 proteins were down-regulated. The most protein species that increased significantly in response to Cu treatment involve in stress response and metabolism, while the protein species that decreased involved in transcription and regulation. Taken together, these results indicate a good correlation among the morphological, ionic and molecular alterations in sorghum roots exposed to excess copper. Further investigation of these proteins may lead to genetic manipulations to engineer sorghum plants resistant to Cu toxicity.

Technical Abstract: Copper (Cu) is an essential micronutrient for all living organisms, but at elevated concentrations, it is extremely toxic to plants and can inactivate and disturb protein structures. To explore the molecular changes involved in the copper stress response, a study was conducted using the roots of sorghum seedlings. Morphological and ionic changes were observed prominently in the roots when the seedlings of sorghum were exposed to different concentrations (0, 50, and 100 µM) of CuSO4. However, the morphological characteristics were reduced by Cu stress and the most significant growth inhibition was observed in plants treated with the highest concentration of Cu2+ ions (100 µM). In the proteome analysis, high-throughput two-dimensional polyacrylamide gel electrophoresis coupled with MALDI-TOF-TOF mass spectrometry was performed to explore the molecular responses of Cu-induced sorghum seedling roots. In two-dimensional silver-stained gels, a total of 422 differentially expressed proteins (= 1.5-fold) were identified using Progenesis SameSpot software. A total of 21 protein spots (= 1.5-fold) from Cu-induced sorghum roots were analyzed by mass spectrometry. Of the 21 differentially expressed protein spots from Cu-induced sorghum roots, a total of 10 proteins were up-regulated and 11 proteins were down-regulated. The abundance of the most identified protein species from the roots that function in stress response and metabolism was significantly enhanced, while protein species involved in transcription and regulation were severely reduced. Taken together, these results indicate a good correlation among the morphological, ionic and molecular alterations in sorghum seedling roots exposed to excess copper.