LIGHT-REGULATED AND ORGAN-SPECIFIC EXPRESSION OF TYPE-1, TYPE-2, AND TYPE-3 LIGHT-HARVESTING COMPLEX-B MESSENGER-RNAS IN GINKGO-BILOBA
LIGHT-REGULATED AND ORGAN-SPECIFIC EXPRESSION OF TYPE-1, TYPE-2, AND TYPE-3 LIGHT-HARVESTING COMPLEX-B MESSENGER-RNAS IN GINKGO-BILOBA
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DOI：
10.1104/pp.107.2.593
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发表时间：
1995-02-01
期刊：
影响因子：
7.4
通讯作者：
HOHTOLA, A
中科院分区：
文献类型：
--
作者：
CHINN, E;SILVERTHORNE, J;HOHTOLA, A
在先前的研究中(E.Chinn和J.Silverthorne[1993]Factory Physiol 103：727-732)，我们发现裸子植物银杏叶绿素的合成和叶绿体的发育完全依赖于光，光诱导的捕光复合体b(LHCb)mRNAs的表达显著增强。然而，转移到恒定白光下的暗生长幼苗比被子植物幼苗启动光形态建成程序所需的时间明显更长，茎未能完全绿色。我们已经为编码捕光复合体II的主要多肽的mRNAs(Lhcb1、Lhcb2和Lhcb3)制备了类型特异性探针，并用这些探针分析了单个LHCb mRNAs在绿化过程中的表达。所有这三个序列都积累在黑暗生长的幼苗的顶部转移到光中，但正如之前看到的总LHCb mRNAs一样，在光照4d后，所有三个mRNAs的水平都有一个短暂的、可重复的下降。LHCb mRNA水平的这种短暂下降与CHI蓄积的减少并不平行。相比之下，在变绿的深色生长的茎的下部，所有三种LHCb mRNAs的水平都明显较低，CHI的水平也较低。我们的结论是，尽管银杏幼苗的顶端具有黄化和绿色的能力，但银杏幼苗的茎在黑暗中继续发育成木质组织，当幼苗转移到阳光下时，阻止了绿色化。
In a prior study (E. Chinn and J. Silverthorne [1993] Plant Physiol 103: 727-732) we showed that the gymnosperm Ginkgo biloba was completely dependent on light for chlorophyll synthesis and chloroplast development and that expression of light-harvesting complex b (Lhcb) mRNAs was substantially increased by light. However, dark-grown seedlings that were transferred to constant white light took significantly longer than angiosperm seedlings to initiate a program of photomorphogenesis and the stems failed to green completely. We have prepared type-specific probes for mRNAs encoding major polypeptides of light-harvesting complex II (Lhcb1, Lhcb2, and Lhcb3) and have used these to analyze the expression of individual Lhcb mRNAs during greening. All three sequences accumulated in the top portions of dark-grown seedlings transferred to light, but, as was seen previously for total Lhcb mRNAs, there was a transient, reproducible decline in the levels of all three mRNAs after 4 d in the light. This transient decrease in Lhcb mRNA levels was not paralleled by a decrease in Chi accumulation. By contrast, there were significantly lower levels of all three Lhcb mRNAs in the lower portions of greening dark-grown stems as well as lower Chi levels. We conclude that although the tops of the plants have the capacity to etiolate and green, Gingko seedling stems continue a program of development into woody tissue in darkness that precludes greening when the seedlings are transferred to the light.