†Departamento de Biologia Vegetal, Instituto de Biologia, CP 6109, Universidade Estadual de Campinas, CEP 13083-970 Campinas, SP, Brazil.
‡Embrapa Soja, Rodovia Carlos João Strass, s/n°, Acesso Orlando Amaral, Distrito de Warta, CP 231, CEP 86001-970 Londrina, PR, Brazil.
J Agric Food Chem. 2015 May 20;63(19):4708-20. doi: 10.1021/jf5061858. Epub 2015 May 12.
The lignin deposition in the stem of two sugarcane genotypes was assessed on exposure to water stress. The lignin content and the morphoanatomical characterization of the stem indicated that IACSP94-2094 plants are more lignified than those of IACSP95-5000 genotype, under normal water supply conditions, which was especially associated with higher lignin contents in the rind of mature internodes. Water deficit had negative impact on the biomass production, mostly with IACSP94-2094 plants, possibly due to stress severity or higher susceptibility of that genotype during the stem-lengthening phase. Water deficit led to significant alterations in the expression levels of lignin biosynthesis genes and led to an approximate 60% increase of lignin content in the rind of young internodes in both genotypes. It is concluded that the young rind region was more directly affected by water stress and, depending on the genotype, a higher lignin accumulation may occur in the stem, thus implying lower quality biomass for bioethanol production.
在暴露于水分胁迫下，评估了两种甘蔗基因型茎中的木质素沉积情况。木质素含量和茎的形态解剖学特征表明，在正常供水条件下，IACSP94-2094 植株比 IACSP95-5000 基因型的木质化程度更高，这主要与成熟节间的外皮中木质素含量较高有关。水分亏缺对生物量的产生有负面影响，主要是对 IACSP94-2094 植株的影响，这可能是由于该基因型在茎伸长阶段受到的胁迫更为严重或敏感性更高。水分亏缺导致木质素生物合成基因的表达水平发生显著变化，并导致两个基因型中幼节间外皮的木质素含量增加约 60%。研究结论认为，幼皮区更容易受到水分胁迫的直接影响，而且根据基因型的不同，木质素在茎中可能会有更高的积累，从而导致用于生产生物乙醇的生物质质量下降。
