Molecular and Pathological Factors involved in Sustainable Wood Quality

一般来说，一棵树在生理正常的条件下产生可持续的木材。当一棵树在生理上远离正常状态时，它可能会产生无序的木材。换句话说，生物和非生物胁迫会扰乱“可持续”的木材质量。各种遗传因素参与了这一过程，也就是正常的“可持续”木材形成。在胁迫因素中，我们重点研究了抗真菌和耐寒基因。针对生物胁迫，二苯乙烯合成酶的特点是在克隆后利用异源表达。针对非生物胁迫，脱水蛋白已被克隆，目前正在进行生理、转基因和分子研究。我们提出了与抗真菌和耐寒因素有关的“可持续”木材质量或木材形成的可靠分子基础。体外培养系统使复杂的非生物分析变得相当简单。在这里，研究了非生物胁迫，特别是温度和重金属的影响。培养系统的反应是产生次生代谢物，尤其是儿茶素，以尽可能保持生理正常状态。此外，次生代谢物在清除活性氧和解毒锰离子方面也起着重要作用。除了对木材标本进行显微分析外，还对患病树木的生理方面进行了检查，例如用声发射技术(AE)。研究结果表明，边材的导水率是维持树木健康的最重要因素，揭示了木材质量或可持续木材质量对森林健康和健康的分子和病理学基础。

Generally speaking, a tree produces sustainable wood under physiologically normal condition. When a tree is physiologically apart far from the normal condition, it may produce disordered wood. In other words, biotic and abiotic stresses disturb "sustainable" wood quality. Various genetic factors are involved in the process, or normal "sustainable" wood formation. Among the stress factors, we focused on anti-fungal and cold tolerant genes. Against the biotic stress, stilbene synthases have characterized by using heterologous expression after the cDNA cloning. Against the abiotic stress, dehydrin has cloned, being characterized by physiological, transgenic, and molecular studies. We have presented a reliable molecular basis on the "sustainable" wood quality or wood formation, in relation to anti-fungal and cold torelant factors.In vitro culture system makes complex abiotic analyses rather simple. Here, the effect of abiotic stress, especially temperature and a heavy metal, had examined. The culture system responded to produce secondary metabolites, especially catechins, in order to keep physiologically normal condition as far as possible. Furthermore, the secondary metabolites played an important role for scavenging active oxygen and detoxification of Mn ions.The field surveys on the health of conifer plantations were made covering wide area from the subarctic to temperate zones. In addition to microscopic analysis of wood specimens, physiological aspects were checked in diseased trees, for instance with acoustic emission technique (AE). The results indicated that the water conductivity of sapwood is most important to keep trees healthy.Altogether, the studies have revealed molecular and pathological bases in forest health and healthiness in the wood quality, or sustainable wood quality.