Characterisation of rapid alkalinisation factors in Physcomitrium patens reveals functional conservation in tip growth
Characterisation of rapid alkalinisation factors in Physcomitrium patens reveals functional conservation in tip growth
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立碗藓快速碱化因子的表征揭示了尖端生长的功能保守
DOI：
10.1111/nph.17942
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发表时间：
2022
期刊：
影响因子：
9.4
通讯作者：
Fujita Tomomichi
中科院分区：
文献类型：
--
作者：
Ginanjar Eggie Febrianto;Teh Ooi-kock;Fujita Tomomichi
小信号肽是植物细胞间通讯的关键分子。富含半胱氨酸的信号肽，快速碱化因子（RALF）家族参与多种发育和胁迫反应，并在陆地植物进化过程中大大扩展，这意味着RALF家族中的新功能化。然而，当陆地植物第一次获得RALF时，RALF的祖先作用仍然未知。在这里，我们使用功能缺失突变体，过表达子以及荧光蛋白标记的报告基因系对BratitePhyscomitrium patents中的三个RALF中的两个进行了功能表征。我们发现PpRALF 1和PpRALF 2在促进原丝体顶端生长和伸长方面具有重叠的功能，在促进根尖生长方面显示出与拟南芥RALF 1同源的功能。虽然这两个PpRALF分泌到质膜上的PpRALF1对称定位，PpRALF2显示出极化定位在生长的尖端。值得注意的是，PpRALF1的蛋白水解切割是其功能所必需的。我们的数据揭示了RALF功能的可能进化起源，并表明RALF的功能分化是必不可少的，以驱动复杂的形态发生，并促进其他新的过程中的陆地植物。
Small signalling peptides are key molecules for cell‐to‐cell communications in plants. The cysteine‐rich signalling peptide, rapid alkalinisation factors (RALFs) family are involved in diverse developmental and stress responses and have expanded considerably during land plant evolution, implying neofunctionalisations in the RALF family. However, the ancestral roles of RALFs when land plant first acquired them remain unknown.Here, we functionally characterised two of the three RALFs in bryophytePhyscomitrium patensusing loss‐of‐function mutants, overexpressors, as well as fluorescent proteins tagged reporter lines.We showed that PpRALF1 and PpRALF2 have overlapping functions in promoting protonema tip growth and elongation, showing a homologous function as the Arabidopsis RALF1 in promoting root hair tip growth. Although both PpRALFs are secreted to the plasma membrane on which PpRALF1 symmetrically localised, PpRALF2 showed a polarised localisation at the growing tip. Notably, proteolytic cleavage of PpRALF1 is necessary for its function.Our data reveal a possible evolutionary origin of the RALF functions and suggest that functional divergence of RALFs is essential to drive complex morphogenesis and to facilitate other novel processes in land plants.