THE NEVER RIPE MUTATION BLOCKS ETHYLENE PERCEPTION IN TOMATO
THE NEVER RIPE MUTATION BLOCKS ETHYLENE PERCEPTION IN TOMATO
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DOI：
10.1105/tpc.6.4.521
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发表时间：
1994-04-01
期刊：
影响因子：
11.6
通讯作者：
KLEE, HJ
中科院分区：
文献类型：
--
作者：
LANAHAN, MB;YEN, HC;KLEE, HJ
对番茄果实成熟突变体的幼苗进行了乙烯反应能力的筛选。乙烯在所有番茄成熟突变体的黄化下胚轴中诱导了三重反应，除了一个永不成熟的突变体(Nr)。我们的结果表明，该突变体的不成熟是由乙烯不敏感引起的。分离分析表明，与Nr相关的乙烯不敏感是一个单一的共显性性状，并且是多效性的，阻碍了花的衰老和脱落以及叶柄的内向反应。在正常的番茄花中，花瓣脱落和衰老发生在花开放后4-5天，并在果实膨大之前。如果没有受精，花梗脱落发生在花瓣衰老后5-8天。如果没有受精，Nr花无限期地附着在植物上，花瓣保持存活和膨大的时间是正常花瓣的四倍多。Nr植株的果实发育没有花瓣衰老；花瓣和国歌保持连接，直到它们被膨胀的子房物理移位。对1-氨基环丙烷-1-羧酸(ACC)合酶过表达植物的分析表明，它们是Nr植物的表型对立面。ACC合成酶在番茄植株中的结构性表达导致植株许多组织产生高水平的乙烯，并诱导叶柄膨大和花的早衰和脱落，通常在开花前。它们对ACC合酶过表达基因叶片的衰老没有明显的影响，这表明虽然乙烯可能是重要的，但它不足以引起番茄叶片的衰老；其他信号显然参与其中。
Seedlings of tomato fruit ripening mutants were screened for their ability to respond to ethylene. Ethylene induced the triple response in etiolated hypocotyls of all tomato ripening mutants tested except for one, Never ripe (Nr). Our results indicated that the lack of ripening in this mutant is caused by ethylene insensitivity. Segregation analysis indicated that Nr-associated ethylene insensitivity is a single codominant trait and is pleiotropic, blocking senescence and abscission of flowers and the epinastic response of petioles. In normal tomato flowers, petal abscission and senescence occur 4 to 5 days after the flower opens and precede fruit expansion. If fertilization does not occur, pedicel abscission occurs 5 to 8 days after petal senescence. If unfertilized, Nr flowers remained attached to the plant indefinitely, and petals remained viable and turgid more than four times longer than their normal counterparts. Fruit development in Nr plants was not preceded by petal senescence; petals and anthem remained attached until they were physically displaced by the expanding ovary. Analysis of engineered 1-aminocyclopropane-1-carboxylate (ACC) synthase-overexpressing plants indicated that they are phenotypic opposites of Nr plants. Constitutive expression of ACC synthase in tomato plants resulted in high rates of ethylene production by many tissues of the plant and induced petiole epinasty and premature senescence and abscission of flowers, usually before anthesis. Them were no obvious effects on senescence in leaves of ACC synthase overexpressers, suggesting that although ethylene may be important, it is not sufficient to cause tomato leaf senescence; other signals are clearly involved.