Yang Xingyan, Wang Bochu, Farris Ben, Clark Greg, Roux Stanley J
Key Laboratory of Biorheological Science and Technology, Ministry of Education, Bioengineering College, Chongqing University, Chongqing, 400030, China.
Key Laboratory of Biorheological Science and Technology, Ministry of Education, Bioengineering College, Chongqing University, Chongqing, 400030, China
Plant Cell Physiol. 2015 Nov;56(11):2197-206. doi: 10.1093/pcp/pcv134. Epub 2015 Sep 27.
When plant primary roots grow along a tilted surface that is impenetrable, they can undergo a slanted deviation from the direction of gravity called skewing. Skewing is induced by touch stimuli which the roots experience as they grow along the surface. Touch stimuli also induce the release of extracellular ATP (eATP) into the plant's extracellular matrix, and two apyrases (NTPDases) in Arabidopsis, APY1 and APY2, can help regulate the concentration of eATP. The primary roots of seedlings overexpressing APY1 show less skewing than wild-type plants. Plants suppressed in their expression of APY1 show more skewing than wild-type plants. Correspondingly, chemical inhibition of apyrase activity increased skewing in mutants and wild-type roots. Exogenous application of ATP or ATPγS also increased skewing in wild-type roots, which could be blocked by co-incubation with a purinergic receptor antagonist. These results suggest a model in which gradients of eATP set up by differential touch stimuli along roots help direct skewing in roots growing along an impenetrable surface.
当植物的初生根沿着不可穿透的倾斜表面生长时，它们会发生一种与重力方向倾斜的偏差，称为倾斜生长。倾斜生长是由根在沿着表面生长时所经历的触觉刺激诱导的。触觉刺激还会诱导细胞外ATP（eATP）释放到植物的细胞外基质中，拟南芥中的两种双磷酸酶（NTPDases），即APY1和APY2，可以帮助调节eATP的浓度。过表达APY1的幼苗的初生根比野生型植物表现出更少的倾斜生长。APY1表达受到抑制的植物比野生型植物表现出更多的倾斜生长。相应地，双磷酸酶活性的化学抑制增加了突变体和野生型根的倾斜生长。外源施加ATP或ATPγS也增加了野生型根的倾斜生长，这可以通过与嘌呤能受体拮抗剂共同孵育来阻断。这些结果提出了一个模型，其中沿着根的不同触觉刺激所建立的eATP梯度有助于引导沿着不可穿透表面生长的根的倾斜生长。
