J Integr Plant Biol ›› 2015, Vol. 57 ›› Issue (6): 534-549.DOI: 10.1111/jipb.12283

Special Issue: Abiotic Stresses

• Molecular Physiology • Previous Articles     Next Articles

Improved oxidative tolerance in suspension-cultured cells of C4-pepctransgenic rice by H2O2 and Ca2+ under PEG-6000

Baoyun Qian1,2,3, Xia Li1,3*, Xiaolong Liu1,2,3 and Man Wang1,3   

  1. 1Institute of Food Crops, Jiangsu Academy of Agricultural Sciences, Jiangsu High Quality Rice Research and Development Center, Nanjing Branch, China National Center for Rice Improvement, Nanjing, China
    2College of Life Sciences, Nanjing Agricultural University, Nanjing, China
    3Provincial Key Laboratory of Agrobiology, Jiangsu Academy of Agricultural Sciences, Nanjing, China
  • Received:2014-06-12 Accepted:2014-09-16 Published:2014-09-17
  • About author:*Correspondence: E-mail: jspplx@jaas.ac.cn

Abstract:

To understand the molecular responses of PC (Overexpressing the maize C4-pepc gene, which encodes phosphoenolpyruvate carboxylase (PEPC)), to drought stress at cell level, we analyzed changes in the levels of signaling molecules (hydrogen peroxide (H2O2), calcium ion (Ca2+), and nitric oxide (NO)) in suspension-cultured PC and wild-type (WT) rice (Oryza sativa L.) cell under drought stress induced by 20% polyethylene glycol 6000 (PEG-6000). Results demonstrated that PC improved drought tolerance by enhancing antioxidant defense, retaining higher relative water content, survival percentages, and dry weight of cells. In addition, PEPC activity in PC under PEG treatment was strengthened by addition of H2O2 inhibitor, dimethylthiourea (DMTU) and NO synthesis inhibitor, 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO), respectively, while that in PC was weakened by addition of free calcium chelator, ethylene glycol-bis(b-aminoethylether)-N,N,N′,N′-tetraacetic acid (EGTA) + calcium channel outflow inhibitor, ruthenium red (RR) + plasma membrane channel blocker La(NO3)3, but EGTA + RR did not. Results also showed that NO and Ca2+ was lying downstream of H2O2 in drought-induced signaling. Calcium ion was also involved in the expression of C4-pepc in PC. These results suggested that PC could improve oxidative tolerance in suspension-cultured cells and the acquisition of this tolerance required downregulation of H2O2 and the entry of extracellular Ca2+ into cells across the plasma membrane for regulation of PEPC activity and C4-pepc expression.

 

Qian B, Li X, Liu X, Wang M (2015) Improved oxidative tolerance in suspension‐cultured cells of C4-pepctransgenic rice by H2O2 and Ca2+ under PEG‐6000. J Integr Plant Biol 57: 534–549. doi: 10.1111/jipb.12283

Research on transgenic rice lines expressing high levels of C4-pepc (hereafter, PC lines) showed that PC could improve oxidative tolerance via the down-regulation of H2O2 and the entry of extracellular Ca2+ into cells across the plasma membrane for regulation of PEPC activity and C4-pepc expression.

Key words: Calcium, drought, hydrogen peroxide, phosphoenolpyruvate carboxylase, rice (Oryza sativa L.)

Editorial Office, Journal of Integrative Plant Biology, Institute of Botany, CAS
No. 20 Nanxincun, Xiangshan, Beijing 100093, China
Tel: +86 10 6283 6133 Fax: +86 10 8259 2636 E-mail: jipb@ibcas.ac.cn
Copyright © 2020 by the Institute of Botany, the Chinese Academy of Sciences
Online ISSN: 1744-7909 Print ISSN: 1672-9072 CN: 11-5067/Q
网站备案号:京ICP备16067583号-22