Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
College of Computer Science, Sichuan University, Chengdu, 610065, China.
Adv Sci (Weinh). 2024 May;11(20):e2306767. doi: 10.1002/advs.202306767. Epub 2024 Mar 29.
Plant movements for survival are nontrivial. Antheridia in the moss Physcomitrium patens (P. patens) use motion to eject sperm in the presence of water. However, the biological and mechanical mechanisms that actuate the process are unknown. Here, the burst of the antheridium of P. patens, triggered by water, results from elastic instability and is determined by an asymmetric change in cell geometry. The tension generated in jacket cell walls of antheridium arises from turgor pressure, and is further promoted when the inner walls of apex burst in hydration, causing water and cellular contents of apex quickly influx into sperm chamber. The outer walls of the jacket cells are strengthened by NAC transcription factor VNS4 and serve as key morphomechanical innovations to store hydrostatic energy in a confined space in P. patens. However, the antheridium in liverwort Marchantia polymorpha (M. polymorpha) adopts a different strategy for sperm release; like jacket cell outer walls of P. patens, the cells surrounding the antheridium of M. polymorpha appear to play a similar role in the storage of energy. Collectively, the work shows that plants have evolved different ingenious devices for sperm discharge and that morphological innovations can differ.
植物为了生存而进行的运动并非微不足道。藓类植物Physcomitrium patens（P. patens）的精子囊利用运动在有水存在的情况下将精子射出。然而，驱动这一过程的生物学和机械机制尚不清楚。在这里，P. patens 精子囊在水的触发下爆发，这是由于弹性不稳定性引起的，并且由细胞几何形状的不对称变化决定。精子囊中套细胞壁产生的张力来自膨压，当顶端内壁在水合作用下爆裂时，张力进一步增强，导致水和顶端的细胞内容物迅速涌入精子室。套细胞的外壁由 NAC 转录因子 VNS4 加强，是在 P. patens 中储存静水压力能的关键形态力学创新。然而，苔类植物 Marchantia polymorpha（M. polymorpha）的精子囊释放采用了不同的策略；与 P. patens 的套细胞外壁类似，M. polymorpha 精子囊周围的细胞似乎在能量储存中发挥类似的作用。总的来说，这项工作表明，植物已经进化出不同的精子排放精巧装置，并且形态创新可能不同。
