López-Malvar Ana, Malvar Rosa Ana, Butrón Ana, Souto Xose Carlos, Santiago Rogelio
Facultad de Biología, Depto. Biología Vegetal Y Ciencias del Suelo, Agrobiología Ambiental, Calidad de Suelos y Plantas (UVIGO), Unidad Asociada a MBG (CSIC), Universidad de Vigo, As Lagoas Marcosende, Vigo, 36310, Spain.
Misión Biológica de Galicia (CSIC), Depto. Producción Vegetal, Pazo de Salcedo, Carballeira 8, Pontevedra, 36143, Spain.
BMC Plant Biol. 2025 Jan 6;25(1):18. doi: 10.1186/s12870-024-05990-w.
The crosslinking of maize cell wall components, particularly mediated by the formation of ferulic acid dimers or diferulates, has been associated with important crop valorization traits such as increased pest resistance, lower forage digestibility, or reduced bioethanol production. However, these relationships were based on studies performed using diverse unrelated inbred lines and/or populations, so genetic background could interfere on these associations.
In the present research, the success of a pedigree selection program aimed to obtain inbred lines from a common antecessor with contrasting diferulate concentration was evaluated. From the 10 inbreds lines developed we could validate the success of the breeding program, obtaining 4 inbred lines with significant contrating values of total diferulate content in the pith tissues (two of each group): high (X̅= 0.69 mg/g of DW) and low (X̅= 0.35 mg/g). Ferulate changes in the same way were also observed: high (X̅= 3.09 mg/g of DW) and low (X̅= 1.62 mg/g). On the other hand, we found strong and positive correlations between DFAT and individual dimers, and moderate negative correlations between total DFAT and a main cell wall component such as cellulose. However, we did not find a significant effect of DFAT on maize valorization traits, except of a negative effect of DFAT on the concentration of sugars released after the enzimatic hydrolysis of the pith tissues. Interestingly, increasing DFAT in the pith does not seem to affect the digestibility of the forage or the saccharification of the stover residue, highlighting that changes in a specific tissue do not encompass correlated changes in other resources.
Overall, we have obtained contrasting inbred lines with diferulates concentration, which could be uselful in further studies focussing in the identification of regions/genes predominantly involved in the hydroxycinnamate biosynthesis pathway and cell wall crosslinking network.
玉米细胞壁成分的交联，特别是由阿魏酸二聚体或二阿魏酸酯的形成介导的交联，与重要的作物增值性状有关，如增强的抗虫性、较低的饲料消化率或减少的生物乙醇产量。然而，这些关系是基于使用不同的不相关自交系和/或群体进行的研究，因此遗传背景可能会干扰这些关联。
在本研究中，评估了一个系谱选择计划的成功性，该计划旨在从具有不同二阿魏酸酯浓度的共同祖先中获得自交系。从育成的10个自交系中，我们可以验证育种计划的成功，获得4个自交系，其髓组织中总二阿魏酸酯含量具有显著的对比值（每组两个）：高（X̅ = 0.69 mg/g干重）和低（X̅ = 0.35 mg/g）。阿魏酸也以同样的方式变化：高（X̅ = 3.09 mg/g干重）和低（X̅ = 1.62 mg/g）。另一方面，我们发现二阿魏酸酯总量（DFAT）与单个二聚体之间存在强正相关，而总DFAT与主要细胞壁成分如纤维素之间存在中度负相关。然而，我们没有发现DFAT对玉米增值性状有显著影响，除了DFAT对髓组织酶解后释放的糖浓度有负面影响。有趣的是，髓中DFAT的增加似乎并不影响饲料的消化率或秸秆残渣的糖化，这突出表明特定组织中的变化并不包括其他资源中的相关变化。
总体而言，我们获得了具有不同二阿魏酸酯浓度的对比自交系，这可能有助于进一步研究，重点是鉴定主要参与羟基肉桂酸生物合成途径和细胞壁交联网络的区域/基因。
