Molecular and Pathological Factors involved in Sustainable Wood Quality

一般来说，树木在生理正常条件下会产生可持续的木材。当一棵树的生理状况远离正常状态时，它可能会产生无序的木材。换句话说，生物和非生物胁迫扰乱了“可持续”的木材质量。这个过程或正常的“可持续”木材形成过程涉及各种遗传因素。在应激因素中，我们重点关注抗真菌和耐寒基因。针对生物胁迫，二苯乙烯合酶的特点是在 cDNA 克隆后使用异源表达。针对非生物胁迫，脱水蛋白已被克隆，并通过生理学、转基因和分子研究对其进行了表征。我们提出了与抗真菌和耐冷因素有关的“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。培养系统响应产生次生代谢产物，特别是儿茶素，以尽可能保持生理正常状态。此外，次生代谢产物对于清除活性氧和解毒锰离子也发挥着重要作用。对针叶林健康状况进行了实地调查，覆盖了从亚北极到温带的广阔区域。除了对木材标本进行显微分析外，还使用声发射技术（AE）等方法检查患病树木的生理状况。结果表明，边材的水传导率对于保持树木健康最为重要。总之，这些研究揭示了森林健康和木材质量健康或可持续木材质量的分子和病​​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.