Stress Tolerance Profiling of a Collection of Extant Salt-Tolerant Rice Varieties and Transgenic Plants Overexpressing Abiotic Stress Tolerance Genes.
Environmental stress tolerance is an important trait for crop improvement. In recent decades, numerous genes that confer tolerance to abiotic stress such as salinity were reported. However, the levels of salt tolerance differ greatly depending on growth conditions, and mechanisms underlying the complicated nature of stress tolerance are far from being fully understood. In this study, we investigated the profiles of stress tolerance of nine salt-tolerant rice varieties and transgenic rice lines carrying constitutively expressed genes that are potentially involved in salt tolerance, by evaluating their growth and viability under salt, heat, ionic and hyperosmotic stress conditions. Profiling of the extant varieties and selected chromosome segment substitution lines showed that salt tolerance in a greenhouse condition was more tightly correlated with ionic stress tolerance than osmotic stresses. In Nona Bokra, one of the most salt-tolerant varieties, the contribution of the previously identified sodium transporter HKT1;5 to salt tolerance was fairly limited. In addition, Nona Bokra exhibited high tolerance to all the stresses imposed. More surprisingly, comparative evaluation of 74 stress tolerance genes revealed that the most striking effect to enhance salt tolerance was conferred by overexpressing CYP94C2b, which promotes deactivation of jasmonate. In contrast, genes encoding ABA signaling factors conferred multiple stress tolerance. Genes conferring tolerance to both heat and hyperosmotic stresses were preferentially linked to functional categories related to heat shock proteins, scavenging of reactive oxygen species and Ca(2+) signaling. These comparative profiling data provide a new basis for understanding the ability of plants to grow under harsh environmental conditions.
Bioscience and Biotechnology Center, Nagoya University, Chikusa, Nagoya, 464-8601 Japan.
Ken-ichi
K
Kurotani
Bioscience and Biotechnology Center, Nagoya University, Chikusa, Nagoya, 464-8601 Japan.
Kazumasa
K
Yamanaka
Bioscience and Biotechnology Center, Nagoya University, Chikusa, Nagoya, 464-8601 Japan Graduate School of Science, Nagoya University, Chikusa, Nagoya, 464-8601 Japan.
Yosuke
Y
Toda
Bioscience and Biotechnology Center, Nagoya University, Chikusa, Nagoya, 464-8601 Japan National Institute of Agrobiological Sciences, Kannondai, Tsukuba, 305-8602 Japan.
Daisuke
D
Ogawa
Bioscience and Biotechnology Center, Nagoya University, Chikusa, Nagoya, 464-8601 Japan.
Maiko
M
Tanaka
Bioscience and Biotechnology Center, Nagoya University, Chikusa, Nagoya, 464-8601 Japan.
Hirotsugu
H
Kozawa
National Institute of Agrobiological Sciences, Kannondai, Tsukuba, 305-8602 Japan Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657 Japan.
Hidemitsu
H
Nakamura
National Institute of Agrobiological Sciences, Kannondai, Tsukuba, 305-8602 Japan Lowland Farming Research Division, NARO Kyushu Okinawa Agricultural Research Center, Izumi 496, Chikugo, Fukuoka, 833-0041 Japan.
Makoto
M
Hakata
National Institute of Agrobiological Sciences, Kannondai, Tsukuba, 305-8602 Japan.
Hiroaki
H
Ichikawa
Bioscience and Biotechnology Center, Nagoya University, Chikusa, Nagoya, 464-8601 Japan.
Tsukaho
T
Hattori
Bioscience and Biotechnology Center, Nagoya University, Chikusa, Nagoya, 464-8601 Japan takeda@agr.nagoya-u.ac.jp.
Shin
S
Takeda
D003517:Cyclopentanes / Q000494:pharmacology; D055864:Droughts; D018506:Gene Expression Regulation, Plant; D006358:Hot Temperature; D012275:Oryza / Q000187:drug effects / Q000235:genetics*; D009997:Osmotic Pressure / Q000187:drug effects; D054883:Oxylipins / Q000494:pharmacology; D010940:Plant Proteins / Q000235:genetics*; D030821:Plants, Genetically Modified / Q000187:drug effects / Q000235:genetics* / Q000502:physiology*; D055051:Salt-Tolerant Plants / Q000187:drug effects / Q000235:genetics*; D012965:Sodium Chloride / Q000494:pharmacology
D003517:Cyclopentanes; D054883:Oxylipins; D010940:Plant Proteins; D012965:Sodium Chloride; C011006:jasmonic acid
Abiotic stress; Full-length cDNA overexpression; Jasmonate; Rice; Salt tolerance