Distinct ethylene- and tissue-specific regulation of β-1,3-glucanases and chitinases during pea seed germination
Distinct ethylene- and tissue-specific regulation of β-1,3-glucanases and chitinases during pea seed germination
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DOI：
10.1007/s004250050622
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发表时间：
1999-08
期刊：
影响因子：
4.3
通讯作者：
L. Petruzzelli;C. Kunz;R. Waldvogel;F. Meins Jr.;G. Leubner‐Metzger
中科院分区：
文献类型：
--
作者：
L. Petruzzelli;C. Kunz;R. Waldvogel;F. Meins Jr.;G. Leubner‐Metzger
研究了β-1，3-葡聚糖酶(β-Glu)和几丁质酶(Chn)在豌豆萌发的种皮、子叶和胚轴中的表达。CV。‘意式咖啡’种子。胚轴有较高浓度的β、Glu和Chn活性。单独用乙烯或与乙烯作用抑制剂2，5-降冰片二烯联合处理表明，在开始吸胀后的前20 小时内，胚轴中GLU活性的早期4倍诱导是不依赖乙烯的。在最初的增加之后，在胚轴中开始了4倍的乙烯依赖诱导，开始于50 h，也就是在乙烯释放开始和胚根出现之后。在整个萌发过程中，子叶中的β-Glu活性逐渐增加，并且不依赖于乙烯。相反，胚轴中的乙烯非依赖性Chn活性在胚轴开始出现后略有增加，在子叶中保持在一个恒定的低水平。免疫失活分析和免疫印迹分析表明，胚轴早期的β谷氨酸活性是由于54 kDa的抗原，而晚期诱导是由于34.5 kDa的抗原，很可能是乙烯诱导的I类βGlu G2被描述为未成熟的豌豆豆荚。胚轴中Chn的增加与26 kDa的抗原有关，而另外的32 kDa和20 kDa的抗原的数量大致保持不变。因此，在豌豆种子萌发过程中，乙烯依赖和非乙烯依赖的途径调节β谷氨酸和Chn。这种调控模式不同于叶片和未成熟的豆荚，也不同于发芽烟草种子的调控模式。讨论了这一调控的功能意义及其内在机制。
The expression of β-1,3-glucanase (βGlu) and chitinase (Chn) was investigated in the testa, cotyledons, and embryonic axis of germinatingPisum sativumL. cv. `Espresso generoso' seeds. High concentrations of βGlu and Chn activity were found in the embryonic axis. Treatment with ethylene alone or in combination with the inhibitor of ethylene action 2,5-norbornadiene showed that an early, 4-fold induction of βGlu activity in the embryonic axis during the first 20 h after the start of imbibition is ethylene-independent. This initial increase was followed by a later 4-fold ethylene-dependent induction in the embryonic axis starting at 50 h, which is after the onset of ethylene evolution and after completion of radicle emergence. The βGlu activity in cotyledons increased gradually throughout germination and was ethylene-independent. In contrast, the ethylene-independent Chn activity increased slightly after the onset of radical emergence in the embryonic axis and remained at a constant low level in cotyledons. Immunoinactivation assays and immunoblot analyses suggest that early βGlu activity in the embryonic axis is due to a 54-kDa antigen, whereas late induction is due to a 34.5-kDa antigen, which is likely to be the ethylene-inducible class I βGlu G2 described for immature pea pods. Increases in Chn in the embryonic axis were correlated with a 26-kDa antigen, whereas amounts of the additional 32- and 20-kDa antigens remained roughly constant. Thus, ethylene-dependent and ethylene-independent pathways regulate βGlu and Chn during pea seed germination. The pattern of regulation differs from that of leaves and immature pods, and from that described for germinating tobacco seeds. The functional significance of this regulation and its underlying mechanisms are discussed.