Fast-growing plants have high carbon demands during periods of fast growth. The high carbon demand during bud break may exceed the carbon supplied by current photosynthesis in evergreen species 25 and also depend partly on the NSC pool. The lack of photosynthetically active tissues at bud break results in broad-leaved trees that are dependent on last season’s carbon reserves for flushing 24. The NSC concentration has been observed to decrease sharply in response to the increased carbon demands during flushing or bud break 16, 17, 18. NSCs are the most important Carbon reserves in the tissues of deciduous and evergreen tree species and serve as carbon sources to satisfy the carbon demand during the flushing of new leaves and shoots in spring 16, 17, 18, 23. The NSC pool is depleted when demand exceeds supply, such as when metabolism and growth requirements are high or when the production of photoassimilates is limited and is refilled when the supply exceeds demand, such as when metabolism and growth requirements are low 1, 7, 21, 22. Recent studies have suggested that a large fraction of a tree’s annual Carbon budget is allocated to the NSC pool 19, 20. Previous investigations have usually focused on the responses of NSCs to drought stress 12, 13, 14, treeline 5, 15 and flushing or bud break 16, 17, 18. Once mobilized, NSCs can be used to support metabolism, structural growth, defense and reproduction 9, 10, 11. ![]() NSCs can provide a temporary source of carbon when current photosynthesis cannot meet the immediate carbon demands of the plant. As major components of the carbon reserves, NSCs can be remobilized for use and play a fundamental role in plant germination, growth, reproduction, defense and survivorship under stress 1, 2, 3, 8. The NSC pool is the sum of soluble sugars and starch 5, 6, 7. SCs, including lignin, cellulose, hemicelluloses and pectin, are mainly used for the structural growth of plants 4. Our findings provide new insight and a possible rational mechanism explaining the “explosive growth” of Moso bamboo and shed new light on understanding the role of NSCs in the rapid growth of Moso bamboo.Īs the main product of plant photosynthesis, carbohydrates can largely be partitioned into structural carbohydrates (SCs) and non-structural carbohydrates (NSCs) according to their roles 1, 2, 3. The trunk contributed the most NSCs to the shoots. During this period, the NSC content of the leaves, branches, trunks and rhizomes of mature bamboos declined by 1.5, 23, 28 and 5 fold, respectively. Approximately 4 months after shoot emergence, this transfer stopped when the leaves of the young bamboos could independently provide enough photoassimilates to meet the carbon demands of the young bamboos. ![]() At the same time, attached mature bamboos transferred almost all the NSCs of their leaves, branches and especially trunks and rhizomes to the “explosively growing” shoots via underground rhizomes for the structural growth and metabolism of shoots. The results showed that Moso bamboos rapidly completed their height and diameter growth within 38 days. We investigated the dynamics of non-structural carbohydrates (NSCs) in shoots and attached mature bamboos over a 20-month period. However, the underlying mechanism for this “explosive growth” remains poorly understood. ![]() ![]() Moso bamboo can rapidly complete its growth in both height and diameter within only 35–40 days after shoot emergence.
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