[植物生理] 植物再生能力的關鍵？ 20191015 Cell Report

Plasmodesmata
Oct 15, 2019
2 min read

Gradient Expression of Transcription Factor Imposes a Boundary on Organ Regeneration Potential in Plants

Kavya Durgaprasad, Merin V. Roy, Anjali Venugopal M., Abdul Kareem, Kiran Raj, Viola Willemsen, Ari Pekka Mähönen, Ben Scheres, and Kalika Prasad

SUMMARY

A wide variety of multicellular organisms across the kingdoms display remarkable ability to restore their tissues or organs when they suffer damage. However, the ability to repair damage is not uniformly distributed throughout body parts. Here, we unravel the elusive mechanistic basis of boundaries on organ regeneration potential using root tip resection as a model and show that the dosage of gradient-expressed PLT2 transcription factor is the underlying cause. While transient downregulation of PLT2 in distinct set of plt mutant backgrounds renders meristematic cells incapable of regeneration, forced expression of PLT2 acts through auto-activation to confer regeneration potential to the cells undergoing differentiation. Surprisingly, sustained exposure to nuclear PLT2, beyond a threshold, leads to reduction of regeneration potential despite giving rise to longer meristem. Our studies reveal dosage-dependent role of gradient-expressed PLT2 in root tip regeneration and uncouple the size of an organ from its regeneration potential.

專錄因子的漸層表現，在植物中建立了器官再生的邊界

總結

有很廣泛在不同“界”（動物界、植物界等）之中的多細胞生物，擁有很驚人的器官或組織再生的能力，能夠在受到損傷的時候，修復受損的部分。然而，這個再生修補的能力，在整個個體中，卻不一致。在此，我們利用了植物根尖切除的系統，解開了費解的，建立器官再生能力邊界的基礎機制。我們發現，轉錄因子PLT2的漸層表現量的差別，是隱藏在器官再生能力背後的因素。當在特定的多plt基因突變的植株中，暫時性的調降PLT2表現會使得幹細胞區域的細胞無法再生。當強制表現PLT2的時候，經由一個自體激發的機制，會給予已經分化的細胞再生的潛力。令人感到驚訝的是，當長時間的暴露在過多的PLT2後，即使植物的根因此擁有了較長的幹細胞區間，整體再生能力的卻會減低。我們的研究顯示了，漸層式表現的PLT2在植物根部對於再生能力的調控是根據表現量上升而有所增加。但是這個再生潛力，與整個器官的大小，並沒有絕對的關連性。