In maize, immunoprecipitation assays have shown that CycD2;2 interacts with KRPs. However, evidence on CycD2;2 or KRPs localization and their possible interaction in specific tissues is lacking and its physiological consequence is still unknown. This work explores the spatiotemporal presence of CyclinD2s and KRPs, cell cycle regulators, during maize seed germination (18 and 36 h) after soaking on glucose or sucrose (120 mM). CyclinD2s are positive actors driving proliferation; KRPs are inhibitors of the main kinase controlling proliferation (a negative signal that slows down the cell cycle). Cell cycle proteins were analyzed by immunolocalization on longitudinal sections of maize embryo axis in seven different tissues or zones (with different proliferation or differentiation potential) and in the nucleus of their cells. Results showed a prevalence of these cell cycle proteins on embryo axes from dry seeds, particularly, their accumulation in nuclei of radicle cells. The absence of sugar caused the accumulation of these regulators in different proliferating zones. CyclinD2 abundance was reduced during germination in the presence of sucrose along the embryo axis, while there was an increase at 36 h on glucose. KRP proteins showed a slight increase at 18 h and a decrease at 36 h on both sugars. There was no correlation between cell cycle regulators/DNA co-localization on both sugars. Results suggest glucose induced a specific accumulation of each cell cycle regulator depending on the proliferation zone as well as nuclear localization which may reflect the differential morphogenetic program regarding the proliferation potential in each zone, while sucrose has a mild influence on both cell cycle proteins accumulation during germination. Whenever CycD2s were present in the nucleus, KRPs were absent after treatment with either sugar and at the two imbibition times analyzed, along the different embryo axe zones.

在玉米中，免疫沉淀分析表明 CycD2;2 与 KRP 相互作用。然而，缺乏有关 CycD2;2 或 KRP 定位及其在特定组织中可能相互作用的证据，其生理后果仍未知。这项工作探讨了玉米种子在葡萄糖或蔗糖 (120 mM) 浸泡后发芽过程中（18 小时和 36 小时）细胞周期调节剂 CyclinD2 和 KRP 的时空存在情况。CyclinD2 是推动增殖的积极因素；KRP 是控制增殖的主要激酶（减慢细胞周期的负信号）的抑制剂。通过免疫定位对玉米胚轴的七个不同组织或区域（具有不同的增殖或分化潜力）及其细胞核中的纵向切片进行细胞周期蛋白分析。结果显示，这些细胞周期蛋白在干种子的胚轴上普遍存在，特别是它们在胚根细胞核中的积累。糖的缺乏导致这些调节因子在不同的增殖区积累。在胚胎轴存在蔗糖的情况下，CyclinD2 丰度在萌发过程中降低，而在葡萄糖存在下，CyclinD2 丰度在 36 小时时增加。两种糖的 KRP 蛋白在 18 小时时略有增加，在 36 小时时略有减少。细胞周期调节剂/DNA 在两种糖上的共定位之间不存在相关性。结果表明，葡萄糖诱导每个细胞周期调节剂的特定积累，具体取决于增殖区域以及核定位，这可能反映了每个区域增殖潜力的不同形态发生程序，而蔗糖对两种细胞周期蛋白的积累有轻微影响。发芽。每当细胞核中存在 CycD2 时，在用任一糖处理后以及在分析的两个吸胀时间沿不同的胚轴区域，KRP 都不存在。