Light-Dependent Death of Maize <i>lls1</i> Cells Is Mediated by Mature Chloroplasts

• John Gray

  Department of Biological Sciences, The University of Toledo, Toledo, Ohio 43606 (J.G.);

• Diane Janick-Buckner

  Division of Science, Truman State University, Kirksville, Missouri 63501 (D.J.-B., B.B.);

• Brent Buckner

  Division of Science, Truman State University, Kirksville, Missouri 63501 (D.J.-B., B.B.);

• Pam S. Close

  Hickman High School, Columbia, Missouri 65202 (P.S.C.); and

• Gurmukh S. Johal

  Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907 (G.S.J.)

抄録

We reported previously the isolation of a novel cell death-suppressing gene from maize (Zea mays) encoded by the Lls1 (Lethal leaf spot-1) gene. Although the exact metabolic function of LLS1 remains elusive, here we provide insight into mechanisms that underlie the initiation and propagation of cell death associated withlls1 lesions. Our data indicate that lls1lesions are triggered in response to a cell-damaging event caused by any biotic or abiotic agent or intrinsic metabolic imbalance—as long as the leaf tissue is developmentally competent to developlls1 lesions. Continued expansion of these lesions, however, depends on the availability of light, with fluence rate being more important than spectral quality. Double-mutant analysis oflls1 with two maize mutants oil-yellowand iojap, both compromised photosynthetically and unable to accumulate normal levels of chlorophyll, indicated that it was the light harvested by the plant that energized lls1lesion development. Chloroplasts appear to be the key mediators oflls1 cell death; their swelling and distortion occurs before any other changes normally associated with dying cells. In agreement with these results are indications that LLS1 is a chloroplast-localized protein whose transcript was detected only in green tissues. The propagative nature of light-dependentlls1 lesions predicts that cell death associated with these lesions is caused by a mobile agent such as reactive oxidative species. LLS1 may act to prevent reactive oxidative species formation or serve to remove a cell death mediator so as to maintain chloroplast integrity and cell survival.

収録刊行物

• Plant Physiology

  Plant Physiology 130 (4), 1894-1907, 2002-12-01

  Oxford University Press (OUP)

キーワード

• Plant Science
• Genetics
• Physiology

詳細情報

• CRID: 1362262945756117248
• NII論文ID: 80015762055
• DOI: 10.1104/pp.008441
• ISSN: 15322548
• ISSN: 00320889
• Web Site: http://academic.oup.com/plphys/article-pdf/130/4/1894/38691924/plphys_v130_4_1894.pdf
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