REGULATION OF SYNTHESIS OF PROTEINASE INHIBITOR-I AND INHIBITOR-II MESSENGER-RNAS IN LEAVES OF WOUNDED TOMATO PLANTS
REGULATION OF SYNTHESIS OF PROTEINASE INHIBITOR-I AND INHIBITOR-II MESSENGER-RNAS IN LEAVES OF WOUNDED TOMATO PLANTS
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DOI：
10.1007/bf00392137
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发表时间：
1986-01-01
期刊：
影响因子：
4.3
通讯作者：
RYAN, CA
中科院分区：
文献类型：
--
作者：
GRAHAM, JS;HALL, G;RYAN, CA
对番茄叶片中两种可诱导伤害的丝氨酸蛋白酶抑制剂I和II及其mRNAs水平进行了定量研究。MILL。)在用止血器伤害叶子之后的植物。在25年生番茄植株下部叶片上的一次伤害可导致这两种抑制蛋白在伤害后4-6h左右开始在受伤和未受伤的叶片中积累。在接下来的4h内，抑制物积累速率在叶片中最大，然后逐渐下降。到20h时，积累几乎停止。单次伤害后，抑制物I和抑制物II的mRNA(长度分别为600个碱基和760个碱基)在受伤的叶片中开始积累，大约在检测到抑制蛋白之前2小时。两种抑制物的mRNA水平在伤后8h左右达到最大值，然后逐渐下降，两者的表观半衰期均约为10h。每小时连续四次创伤后，两种抑制物的mRNA水平均增加到单次创伤的两倍以上。在多发伤后4h内，抑制因子I的表达约占多聚腺苷酸化的信使核糖核酸(PolyA+)的0.5%，抑制因子II的表达约占总的0.15%。这两种抑制蛋白的积累速度随植物的年龄和生长环境的不同而不同，范围在3到10微克的抑制物i-cntdot之间。H-1.cntdo.(G组织)-1，抑制物II。从受伤和非受伤植物的叶片中分离出细胞核，在以特异抑制物拷贝DNA(CDNAs)为探针的mRNA径流实验中，抑制物I和II的mRNAs的合成至少部分地在转录水平上受到调控。
Levels of two wound-inducible serine proteinase inhibitors, called Inhibitor I and Inhibitor II, and their mRNAs were quantified in leaves of tomato (Lycopersicon esculentum (L.) Mill.) plants after wounding the leaves with a hemostat. A single wound on a lower leaf of 25-old tomato plants caused the accumulation of the two inhibitor proteins in wounded and non-wounded leaves beginning about 4-6 h following wounding. The rate of inhibitor accumulation was maximal in leaves for the next 4 h and then declined. By 20 h the accumulation had nearly ceased. Following a single wound, Inhibitor I mRNA [600 bases in length] and Inhibitor II mRNA (760 bases) began to accumulate in wounded leaves about 2 h before the inhibitor proteins could be detected. The levels of mRNA for both inhibitors reached a maximum at about 8 h following wounding and then decayed, both with apparent half lives of about 10 h. Four consecutive wounds, inflicted hourly, increased the levels of mRNA for both inhibitors to over twice the levels induced by a single wound. Within 4 h following multiple wounds, Inhibitor I mRNA represented about 0.5% of the total polyadenylated mRNA (poly(A+)mRNA) and Inhibitor II mRNA about 0.15% of the total. The rates of accumulation of the two inhibitor proteins varied depending upon the age of the plants and their environment during growth, and ranged between 3 and 10 .mu.g Inhibitor I .cntdot. h-1.cntdot. (g tissue)-1 for Inhibitor I and about half of these rates for Inhibitor II. Nuclei were isolated from leaves of wounded and non-wounded plants, and in mRNA runoff experiments using specific inhibitor copy DNAs (cDNAS) as probes the synthesis of Inhibitor I and II mRNAs were shown to be regulated, at least in part, at the level of transcription.