Carvalho Marcia Eugenia Amaral, Piotto Fernando Angelo, Nogueira Marina Lima, Gomes-Junior Francisco Guilhien, Chamma Helena Maria Carmignani Pescarin, Pizzaia Daniel, Azevedo Ricardo Antunes
Departamento de Genética, Escola Superior de Agricultura "Luiz de Queiroz", Universidade de São Paulo (Esalq/USP), Piracicaba, SP, 13418-900, Brazil.
Departamento de Produção Vegetal, Escola Superior de Agricultura "Luiz de Queiroz", Universidade de São Paulo (Esalq/USP), Piracicaba, SP, 13418-900, Brazil.
Protoplasma. 2018 Jul;255(4):989-999. doi: 10.1007/s00709-018-1210-8. Epub 2018 Jan 21.
Although negative effects on the offspring fitness can be triggered by the mother-plant exposure to environmental stresses, some plants are able to "remember" past incidents and enhance the progeny tolerance. Here, the mineral profile, cytogenetic modifications, and physiological potential of seeds from two tomato cultivars, with contrasting tolerance degrees to cadmium (Cd) toxicity, were evaluated after plant exposure to this metal. Both cultivars exhibited high Cd translocation to the seeds; however, the tolerant tomato accumulated more Cd than did the sensitive one. As a consequence of the Cd accumulation, reductions in the Mn concentration in Cd-challenged plants were detected. Surprisingly, seed germination and vigor were increased in the tolerant tomato cultivar after Cd exposure, despite increases in the chromosomal abnormalities. By contrast, seeds from the sensitive cultivar exhibited no changes in their physiological potential after Cd exposure, despite Cd-induced reductions in the mitotic index. Moreover, bunch position exerted effects on the vigor and type of chromosomal abnormality. The results show that maternal plant exposure to Cd can affect tomato offspring by changing the seed physiological potential, and such effect can be partially explained by alterations in the seed-derived elements (essential and non-essential) and genotype-dependent tolerance mechanisms.
尽管母株暴露于环境胁迫会对后代适应性产生负面影响，但一些植物能够“记住”过去的事件并增强后代的耐受性。在此，对两种对镉（Cd）毒性耐受性不同的番茄品种的植株在接触这种金属后所结种子的矿物质含量、细胞遗传学修饰和生理潜力进行了评估。两个品种的植株都表现出向种子的高镉转运；然而，耐受性番茄比敏感番茄积累了更多的镉。由于镉的积累，检测到镉胁迫植株中锰浓度降低。令人惊讶的是，尽管染色体异常增加，但镉暴露后耐受性番茄品种的种子发芽率和活力有所提高。相比之下，敏感品种的种子在镉暴露后生理潜力没有变化，尽管镉诱导有丝分裂指数降低。此外，果穗位置对活力和染色体异常类型有影响。结果表明，母株接触镉可通过改变种子生理潜力影响番茄后代，这种影响可部分由种子中元素（必需和非必需）的变化以及基因型依赖的耐受机制来解释。
