Somaclonal variation (SV) is observed during micropropagation, especially in organogenic processes when differentiated somatic cells are induced into a pluripotent state. However, the clones obtained show differences in phenotype from each other and from the mother plants, which could be an agricultural problem or an ornamental advantage. Few of the mechanisms associated with how a somatic cell generates phenotypic variation have been elucidated. Recently, our group demonstrated that an albino phenotype produced in Agave in in vitro culture was linked to changes in DNA methylation through the micropropagation process, suggesting a new way to investigate the mechanism. Therefore, here we evaluate the effect of stressful conditions in the culture media on three different phenotypes (green, variegated and albino) of Agaveangustifolia Haw. to determine the changes in DNA methylation linked to SV in the new formed shoots. The effects of nutrient availability and exogen cytokinin concentration in the culture media were evaluated for five months in each phenotype. We observed that a reduction of 25 % in the nutrients in the culture media affected the coloration of green plantlets. On the other hand, a high 6-benzyladenine (BA) concentration exposure (88.8 μM) in the variegated phenotype enhanced organogenic capability, increased phenotypic variation, and changed DNA methylation levels. We have demonstrated that long periods of time under nutrient-limited conditions or high cytokinin concentration provoke changes in DNA methylation levels that increase SV frequency in the newly formed shoots. Epigenetic changes may thus be an overlooked factor in SV induced by culture media stress.

在微繁殖过程中观察到体细胞克隆变异 (SV)，特别是在分化的体细胞被诱导为多能状态时的器官发生过程中。然而，获得的克隆彼此之间以及与母本植物的表型存在差异，这可能是农业问题或观赏优势。与体细胞如何产生表型变异相关的机制很少被阐明。最近，我们的小组证实，患白化病的表型，生产的龙舌兰在体外通过微繁殖过程，培养与 DNA 甲基化的变化有关，这表明了一种研究该机制的新方法。因此，我们在这里评估了培养基中的压力条件对Agaveangustifolia 的三种不同表型（绿色、杂色和白化）的影响哇。确定新形成的枝条中与 SV 相关的 DNA 甲基化的变化。在每个表型中评估了五个月的培养基中营养物质可用性和外源细胞分裂素浓度的影响。我们观察到培养基中营养素减少 25% 会影响绿色小植株的着色。另一方面，杂色表型中的高 6-苄基腺嘌呤 (BA) 浓度暴露 (88.8 μM) 增强了器官发生能力，增加了表型变异，并改变了 DNA 甲基化水平。我们已经证明，长时间在营养有限的条件下或高细胞分裂素浓度下会引起 DNA 甲基化水平的变化，从而增加新形成的枝条中的 SV 频率。因此，表观遗传变化可能是培养基压力诱导的 SV 中被忽视的因素。