Lateral branches (LBs) pruning is performed frequently to keep the tomato plants in optimal growth conditions. However, the suitable pruning length of LBs, as well as the physiological and molecular mechanisms of pruning length on plant growth regulation remains elusive in tomato. The effects of pruning length of LBs from 0 to 20 cm on vegetative growth, reproductive growth, labor costs, hormone metabolism and genes transcripts were evaluated in an indeterminate type tomato cultivar. By comprehensive analysis, we provided evidence that pruning length of LBs at about 6–7 cm was suitable for plant growth, high yield, and low labor costs in tomato production. For mechanisms, appropriate extension of pruning length of LBs increased indole acetic acid (IAA) concentrations in root, which promoted the biosynthesis and upward transport of inactive cytokinins (CKs), as well as root development. Meanwhile, existence of LBs inhibited the auxin outflow of the lower flower stalks by regulating transcripts of AUX1 and PIN . Then, the enhanced concentrations of IAA and CKs in ovary could promote fruit swelling. Additionally, pruning length of LBs also influenced the leaf senescence to control photosynthesis. Taken together, we highlight that pruning length of LBs influence auxin and cytokinins homeostasis in relation to growth and yield in tomato plants.

中文翻译：

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侧枝修剪长度影响番茄生长和产量与生长素 - 细胞分裂素交叉相关

经常进行侧枝 (LBs) 修剪以保持番茄植株处于最佳生长条件。然而，LBs 的适宜修剪长度，以及修剪长度对植物生长调节的生理和分子机制在番茄中仍然难以捉摸。在不确定类型的番茄品种中评估了 0 到 20 厘米的 LB 修剪长度对营养生长、生殖生长、劳动力成本、激素代谢和基因转录的影响。通过综合分析，我们提供了证据表明，LBs 修剪长度在 6-7 cm 左右适合植物生长，产量高，番茄生产劳动力成本低。对于机制，适当延长 LB 的修剪长度会增加根中吲哚乙酸 (IAA) 的浓度，这促进了无活性细胞分裂素（CKs）的生物合成和向上运输，以及根的发育。同时，LBs 的存在通过调节 AUX1 和 PIN 的转录本来抑制下部花茎的生长素外流。然后，子房中IAA和CKs浓度的增加可以促进果实膨大。此外，LBs 的修剪长度也影响叶片衰老以控制光合作用。总之，我们强调 LB 的修剪长度会影响与番茄植物生长和产量相关的生长素和细胞分裂素稳态。LBs 的修剪长度也影响叶片衰老以控制光合作用。总之，我们强调 LB 的修剪长度会影响与番茄植物生长和产量相关的生长素和细胞分裂素稳态。LBs 的修剪长度也影响叶片衰老以控制光合作用。总之，我们强调 LB 的修剪长度会影响与番茄植物生长和产量相关的生长素和细胞分裂素稳态。