THE RESPONSE OF MAIZE SEEDLINGS OF DIFFERENT AGES TO HYPOXIC AND ANOXIC STRESS - CHANGES IN INDUCTION OF ADH1 MESSENGER-RNA, ADH ACTIVITY, AND SURVIVAL OF ANOXIA
THE RESPONSE OF MAIZE SEEDLINGS OF DIFFERENT AGES TO HYPOXIC AND ANOXIC STRESS - CHANGES IN INDUCTION OF ADH1 MESSENGER-RNA, ADH ACTIVITY, AND SURVIVAL OF ANOXIA
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DOI：
10.1104/pp.105.1.53
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发表时间：
1994-05-01
期刊：
影响因子：
7.4
通讯作者：
COBB, BG
中科院分区：
文献类型：
--
作者：
ANDREWS, DL;DREW, MC;COBB, BG
以前我们发现，只有一个短暂的诱导乙醇脱氢酶1（Adh 1）的转录和只有一个小的诱导乙醇脱氢酶（ADH）酶活性在玉米（Zea mays L.）通过暴露于低O-2（D.L.）Andrews，B.G.科布，J.R.约翰逊，M.C. Drew [1993] Plant Physiol 101：403-414）。幼苗根尖在缺氧前进行低氧驯化是ADH完全诱导的必要条件。在这里，我们研究了苗龄对蛋白质含量变化的影响，Adh 1转录诱导，ADH酶活性在5毫米根尖，根轴，和芽的玉米（品种TX 5855）。他们的缺氧生存能力也被记录下来。一些幼苗用4%O-2鼓泡6或18 h（低氧预处理），然后用N-2鼓泡缺氧长达48 h。其他幼苗在缺氧前未进行驯化。在一般情况下，年轻的幼苗有较高的初始（有氧）水平的总蛋白质，Adh 1转录本，ADH活性比幼苗2天以上。对于年轻的幼苗，缺氧单独诱导Adh 1的成绩单，在6至12小时内达到高峰，而ADH活性在整个48小时的治疗增加。对于老苗，缺氧引起的Adh 1转录或ADH活性的小，短暂的诱导。对于任何年龄的幼苗，缺氧都会诱导Adh 1转录本和ADH活性，随后的缺氧会进一步增加年轻幼苗的Adh 1转录本和ADH活性，但在年长幼苗中，这两种活性的增加程度较小。尽管ADH活性的差异，无论是年龄的幼苗的根表现出类似的耐缺氧。因此，驯化的玉米幼苗生存缺氧似乎并不涉及高水平的ADH活性的诱导。
Previously we showed that there is only a transient induction of alcohol dehydrogenase 1 (Adh1) transcripts and only a small induction of alcohol dehydrogenase (ADH) enzyme activity in root tips of maize (Zea mays L.) seedlings subjected to strict anaerobiosis without prior acclimation by exposure to low O-2 (D.L. Andrews, B.G. Cobb, J.R. Johnson, M.C. Drew [1993] Plant Physiol 101: 403-414). Acclimation of root tips of seedlings by low O-2 before anoxia appeared to be necessary for full induction of ADH. Here we have examined the effect of seedling age on changes in the protein content, induction of Adh1 transcripts, and ADH enzyme activity in 5-mm root tips, root axes, and shoots of maize (cv TX5855). Their ability to survive anoxia was also recorded. Some seedlings were sparged with 4% O-2 for 6 or 18 h (a hypoxic pretreatment) followed by anoxia (sparged with N-2) for up to 48 h. Other seedlings were not acclimated before anoxia. In general, younger seedlings had higher initial (aerobic) levels of total protein, Adh1 transcripts, and ADH activity than did seedlings that were 2 d older. For younger seedlings, anoxia alone induced Adh1 transcripts, which reached a peak within 6 to 12 h, whereas ADH activity increased throughout the 48-h treatment. For older seedlings, anoxia caused only a small, transient induction of Adh1 transcripts or ADH activity. For seedlings of either age, hypoxia induced Adh1 transcripts and ADH activity, both of which were increased further by subsequent anoxia in the younger seedlings but to a lesser extent in the older seedlings. Despite differences in ADH activity, roots of seedlings of either age showed a similar resistance to anoxia. Thus, acclimation of maize seedlings to survive anoxia does not appear to be related to induction of high levels of ADH activity.