Phosphorus (P) is one of the macronutrients that is essential for plant growth and development. Anoectochilus roxburghii (Wall.) Lindl., an important orchid species, often encounters low-phosphorus stress during cultivation. Strigolactones (SLs) or their derivatives have recently been defined as novel plant hormones that regulate plant root development. However, it remains unclear whether SLs mediate root growth in response to phosphorus deficiency in A. roxburghii. In this study, the responses of A. roxburghii under P deficiency condition to different levels of SLs were investigated. The results demonstrated that the inhibition effect of low-phosphorus stress on plant growth in A. roxburghii significantly alleviated by SLs application, especially 0.1 mu mol L-1 of SL. The group treated with SL exhibited higher root elongation and lower levels of reactive oxygen species, as well as significantly increased soluble protein content and malonaldehyde. Furthermore, the SL treatment down-regulated the expression of several phosphorus-responsive genes, such as ArPHT6 and ArAP5, suggesting that SLs may promote phosphorus uptake or utilization to mitigate low-phosphorus stress. These findings provide an important new insights into the action mechanisms of SLs' in response to low-phosphorus stress and offer potential application value for cultivation and production of A. roxburghii. Future research will focus on exploring the molecular mechanism between SLs and phosphorus uptake.

来源平台：JOURNAL OF PLANT GROWTH REGULATION