Ozone-Induced Rice Grain Yield Loss Is Triggered via a Change in Panicle Morphology That Is Controlled by ABERRANT PANICLE ORGANIZATION 1 Gene.
Rice grain yield is predicted to decrease in the future because of an increase in tropospheric ozone concentration. However, the underlying mechanisms are unclear. Here, we investigated the responses to ozone of two rice (Oryza Sativa L.) cultivars, Sasanishiki and Habataki. Sasanishiki showed ozone-induced leaf injury, but no grain yield loss. By contrast, Habataki showed grain yield loss with minimal leaf injury. A QTL associated with grain yield loss caused by ozone was identified in Sasanishiki/Habataki chromosome segment substitution lines and included the ABERRANT PANICLE ORGANIZATION 1 (APO1) gene. The Habataki allele of the APO1 locus in a near-isogenic line also resulted in grain yield loss upon ozone exposure, suggesting APO1 involvement in ozone-induced yield loss. Only a few differences in the APO1 amino acid sequences were detected between the cultivars, but the APO1 transcript level was oppositely regulated by ozone exposure: i.e., it increased in Sasanishiki and decreased in Habataki. Interestingly, the levels of some phytohormones (jasmonic acid, jasmonoyl-L-isoleucine, and abscisic acid) known to be involved in attenuation of ozone-induced leaf injury tended to decrease in Sasanishiki but to increase in Habataki upon ozone exposure. These data indicate that ozone-induced grain yield loss in Habataki is caused by a reduction in the APO1 transcript level through an increase in the levels of phytohormones that reduce leaf damage.
Center for Environmental Biology and Ecosystem, National Institute for Environmental Studies, Tsukuba, Ibaraki, 305-8506, Japan; Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8577, Japan.
Keita
K
Tsukahara
Center for Environmental Biology and Ecosystem, National Institute for Environmental Studies, Tsukuba, Ibaraki, 305-8506, Japan.
Hiroko
H
Sawada
Central Research Institute of Electric Power Industry, Abiko, Chiba, 270-1194, Japan.
Yoshihisa
Y
Kohno
Institute of Plant Science and Resources, Okayama University, Kurashiki, Okayama, 710-0046, Japan.
Takakazu
T
Matsuura
Institute of Plant Science and Resources, Okayama University, Kurashiki, Okayama, 710-0046, Japan.
Izumi C
IC
Mori
Crop Development Division, Hokuriku Research Center, NARO Agricultural Research Center, National Agriculture and Food Research Organization, Joetsu, Niigata, 943-0193, Japan.
Tomio
T
Terao
Center for Environmental Biology and Ecosystem, National Institute for Environmental Studies, Tsukuba, Ibaraki, 305-8506, Japan.
Motohide
M
Ioki
Center for Environmental Biology and Ecosystem, National Institute for Environmental Studies, Tsukuba, Ibaraki, 305-8506, Japan; Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8577, Japan.
Masanori
M
Tamaoki
D000040:Abscisic Acid / Q000378:metabolism; D000483:Alleles; D000595:Amino Acid Sequence; D003517:Cyclopentanes / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D012275:Oryza / Q000737:chemistry / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism; D054883:Oxylipins / Q000378:metabolism; D010126:Ozone / Q000378:metabolism*; D062966:Ozone Depletion; D010937:Plant Growth Regulators / Q000378:metabolism; D010940:Plant Proteins / Q000032:analysis / Q000235:genetics; D040641:Quantitative Trait Loci
D003517:Cyclopentanes; D054883:Oxylipins; D010937:Plant Growth Regulators; D010940:Plant Proteins; D010126:Ozone; C011006:jasmonic acid; D000040:Abscisic Acid