Aging is a universal property of multicellular organisms. Although some tree species can live for centuries or millennia, the molecular and metabolic mechanisms underlying their longevity are unclear. To address this, we investigated age-related changes in the vascular cambium from 15- to 667-y-old Ginkgo biloba trees. The ring width decreased sharply during the first 100 to 200 y, with only a slight change after 200 y of age, accompanied by decreasing numbers of cambial cell layers. In contrast, average basal area increment (BAI) continuously increased with aging, showing that the lateral meristem can retain indeterminacy in old trees. The indole-3-acetic acid (IAA) concentration in cambial cells decreased with age, whereas the content of abscisic acid (ABA) increased significantly. In addition, cell division-, cell expansion-, and differentiation-related genes exhibited significantly lower expression in old trees, especially miR166 and HD-ZIP III interaction networks involved in cambial activity. Disease resistance-associated genes retained high expression in old trees, along with genes associated with synthesis of preformed protective secondary metabolites. Comprehensive evaluation of the expression of genes related to autophagy, senescence, and age-related miRNAs, together with analysis of leaf photosynthetic efficiencies and seed germination rates, demonstrated that the old trees are still in a healthy, mature state, and senescence is not manifested at the whole-plant level. Taken together, our results reveal that long-lived trees have evolved compensatory mechanisms to maintain a balance between growth and aging processes. This involves continued cambial divisions, high expression of resistance-associated genes, and continued synthetic capacity of preformed protective secondary metabolites.

中文翻译：

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多方面分析血管的冈比亚细胞揭示了长寿机制的银杏老树。

衰老是多细胞生物的普遍特性。尽管某些树种可以生存数百年或几千年，但其寿命的分子和代谢机制尚不清楚。为了解决这个问题，我们调查了从15岁到667岁的银杏树的血管形成层与年龄相关的变化。在最初的100到200 y内，环的宽度急剧下降，在200 y的年龄后仅略有变化，随之而来的是层状细胞层的减少。相反，随着年龄的增长，平均基础面积增加（BAI）持续增加，这表明外侧分生组织可以保留老树的不确定性。随着年龄的增长，颅内细胞中吲哚-3-乙酸（IAA）的浓度降低，而脱落酸（ABA）的含量则显着增加。此外，细胞分裂，细胞扩增，与分化相关的基因在老树中表现出显着较低的表达，尤其是参与了冈比亚活动的miR166和HD-ZIP III相互作用网络。与疾病抗性相关的基因以及与预先形成的保护性次级代谢产物的合成相关的基因在老树中保持了高表达。对与自噬，衰老和与年龄相关的miRNA相关基因的表达的综合评估，以及对叶片光合作用效率和种子发芽率的分析，表明老树仍处于健康，成熟状态，并且未表现出衰老在整个工厂级别。两者合计，我们的结果表明，长寿树已进化出补偿机制，以维持生长和衰老过程之间的平衡。这涉及持续的冈比亚分裂，