Abstract：
A stoma forms by a series of asymmetric divisions of stomatal lineage precursor cell and the terminal division of a guard mother cell (GMC). GMC division is restricted to once through genetic regulation mechanisms. Here, we show that nitric oxide (NO) is involved in the regulation of the GMC division. NO donor treatment results in the formation of single guard cells (SGCs). SGCs are also produced in plants that accumulate high NO, whereas clustered guard cells (GCs) appear in plants with low NO accumulation. NO treatment promotes the formation of SGCs in the stomatal signalling mutants sdd1, epf1 epf2, tmm1, erl1 erl2 and er erl1 erl2, reduces the cell number per stomatal cluster in the fama-1 and flp1 myb88, but has no effect on stomatal of cdkb1;1 cyca2;234. Aminocyclopropane-1-carboxylic acid (ACC), a positive regulator of GMC division, reduces the NO-induced SGC formation. Further investigation found NO inhibits ACC synthesis by repressing the expression of several ACC SYNTHASE (ACS) genes, and in turn ACC represses NO accumulation by promoting the expression of HEMOGLOBIN 1 (HB1) encoding a NO scavenger. This work shows NO plays a role in the regulation of GMC division by modulating ACC accumulation in the Arabidopsis cotyledon.
摘要：
气孔由气孔谱系前体细胞的一系列不对称分裂和保卫母细胞（GMC）的末端分裂形成。GMC的分裂局限于一次经由过程遗传调控机制。这里,我们表明一氧化氮（NO）参与了GMC分裂的调节。NO供体处理导致单个保卫细胞(SGC)的形成。SGC也在积累高NO的植物中产生，而成簇的保卫细胞（GC）出现在NO积累较低的植物中。NO处理促进气孔信号突变体sdd1，epf1epf2，tmm1，erl1erl2和ererl1erl2中SGC的形成，减少fama-1和flp1myb88中每个气孔簇的细胞数量，但对cdkb1的气孔没有影响。1cyca2;234。氨基环丙烷-1-羧酸(ACC),GMC部门的正调节器，减少NO诱导的SGC形成。进一步研究发现，NO通过抑制几种ACC合成酶（ACS）基因的表达来抑制ACC合成，ACC又通过促进编码NO清除剂的血红蛋白1（HB1）的表达来抑制NO的积累。这项工作表明，NO通过调节拟南芥子叶中ACC的积累在GMC分裂的调节中起作用。
