Dynamic changes in growth characteristics and endogenous hormone contents in the leaves and roots of Sophora davidii seedlings under low-phosphorus stress were studied to provide a reference for further study of the internal regulatory mechanism of the response strategy of this species to low-phosphorus stress. Normal phosphorus (0.5 mmol KH₂PO₄, NP) and low-phosphorus (0.005 mmol KH₂PO₄, LP) levels and different treatment times were applied to study growth characteristics, phosphorus utilization and hormone contents in the leaves and roots of potted Sophora davidii by tissue culture and sand culture. The results first showed that compared with NP, LP significantly decreased the plant height, leaf length, leaf width, leaf area, leaf perimeter and root–shoot ratio by 20.10%, 21.08%, 22.73%, 51.33%, 24.94% and 18.92%, respectively. LP decreased the total root length and root dry weight, and increased the root surface area, average root diameter, root tip number, root volume and dry weight of the aerial part on day 9, but these effects were not significant. Second, compared with NP, LP significantly decreased P contents in the aerial part and roots and P uptake efficiency in the aerial part and roots on day 9 by 23.33%, 53.89%, 14.04% and 58.06%, respectively. LP significantly increased the P utilization efficiency and leaf acid phosphatase (ACP) activity on day 9 by 82.79% and 84.38%, respectively. LP increased root ACP activity on day 9, but the effect was not significant. Third, compared with NP, LP significantly decreased abscisic acid (ABA), cytokinin (CTK) and strigolactone (SL) contents in leaves by 21.52%, 36.65% and 45.86%, respectively, and significantly increased gibberellin (GA) contents in roots by 28.92% on day 9. LP decreased GA contents in leaves and CTK contents in roots and increased indole-3-acetic acid (IAA) contents in leaves and roots and ABA and SL contents in roots on day 9, but these effects were not significant. Correlation analysis indicated that endogenous hormone contents in Sophora davidii leaves and roots under different treatment conditions had certain correlations with growth characteristics. In conclusion, Sophora davidii can improve its P utilization efficiency by changing growth characteristics and endogenous hormones to enhance its adaptive response to low-phosphorus stress.

研究了低磷胁迫下苦参幼苗叶片和根系生长特性和内源激素含量的动态变化，为进一步研究该物种对低磷胁迫响应策略的内在调控机制提供参考。应用正常磷（0.5 mmol KH ₂ PO ₄，NP）和低磷（0.005 mmol KH ₂ PO ₄，LP）水平和不同处理时间研究盆栽叶片和根的生长特性、磷利用和激素含量。槐花组织培养和砂培养。结果首先表明，与NP相比，LP显着降低株高、叶长、叶宽、叶面积、叶周长和根冠比20.10%、21.08%、22.73%、51.33%、24.94%和18.92% ， 分别。LP在第9天降低了总根长和根干重，增加了根表面积、平均根直径、根尖数、根体积和地上部分干重，但这些影响不显着。其次，与NP相比，LP在第9天显着降低了地上部分和根部的P含量以及地上部分和根部的P吸收效率分别降低了23.33%、53.89%、14.04%和58.06%。LP 使第 9 天的磷利用效率和叶酸性磷酸酶 (ACP) 活性分别提高了 82.79% 和 84.38%。LP 在第 9 天增加根 ACP 活性，但效果不显着。第三，与NP相比，LP显着降低叶片脱落酸（ABA）、细胞分裂素（CTK）和独脚金内酯（SL）含量分别为21.52%、36.65%和45.86%，显着增加根中赤霉素（GA）含量第 9 天 28.92%。LP 在第 9 天降低叶片中 GA 含量和根中 CTK 含量，增加叶片和根中吲哚-3-乙酸 (IAA) 含量以及根中 ABA 和 SL 含量，但这些影响不显着. 相关性分析表明，内源性激素含量 第 9 天根中赤霉素 (GA) 含量显着增加 28.92%。LP 降低了叶中 GA 含量和根中 CTK 含量，增加了叶和根中吲哚-3-乙酸 (IAA) 含量以及 ABA 和 SL 含量。在第 9 天生根，但这些影响并不显着。相关性分析表明，内源性激素含量 第 9 天根中赤霉素 (GA) 含量显着增加 28.92%。LP 降低了叶中 GA 含量和根中 CTK 含量，增加了叶和根中吲哚-3-乙酸 (IAA) 含量以及 ABA 和 SL 含量。在第 9 天生根，但这些影响并不显着。相关性分析表明，内源性激素含量不同处理条件下的国槐叶和根与生长特性具有一定的相关性。综上所述，国槐可以通过改变生长特性和内源激素来增强其对低磷胁迫的适应性反应，从而提高其磷的利用效率。