Sugarcane Research Institute, Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture and Rural Affairs, Guangxi Key Laboratory of Sugarcane Genetic Improvement, Guangxi Academy of Agricultural Sciences, Nanning, 530007, Guangxi, China.
Sci Rep. 2024 Oct 9;14(1):23633. doi: 10.1038/s41598-024-74436-y.
Defoliation is a primary agronomic traits, its variation depends on different plant species or cultivars. The present article assess the leaf morphological responses, oxidative metabolites and enzymatic activities at sheath base of sugarcane cultivars during defoliation stage of plant leaves. The mature leaf sheath of GT47 strongly wrapped to the stem, and no stem was exposed. The upper and lower edges of the immature fusing abscission zone were parallel, and slightly lower browning area (+ 3 to + 7 leaf position). The ROC22 cultivar was monitored highest leaf sheath-based cellulose and lignin content, followed by GT60 and GT47. Peroxidase activity was higher in leaf sheath base edge (ROC22) as compare to other cultivars. The malondialdehyde content was found highest in GT60, followed by ROC22, and GT47. The exo-β-1,4-glucanase/ cellobiohydrolase activity was found highest in the margin of GT47 than lateral and medial axis of ROC22 and GT60. The axis activity increased exponentially, and ROC22 gradually decreased from the periphery of the mid-axis and lower than GT47 and GT60 in the lateral and mid-axis of leaf. In conclusion, the mature leaves are easy to defoliate mainly loose leaf sheaths, large leaf sheath inclination angles, more deformation during the growth period of the abscission zone, early with large cracks, and slow browning process. Leaf sheaths with high fibre and lignin content showed significant hardness and thickness. The sugarcane cultivars showed positive correlation between peroxidase and malondialdehyde content with the browning process at the base of mature leaf sheaths.
脱叶是一种主要的农艺性状，其变化取决于不同的植物物种或品种。本文评估了甘蔗品种叶片脱叶期叶片鞘基的叶形态响应、氧化代谢物和酶活性。GT47 的成熟叶鞘紧紧地包裹在茎上，没有露出茎。未成熟的融合离层上下边缘平行，稍低的褐变区（+3 至+7 叶位）。ROC22 品种监测到最高的叶鞘基纤维素和木质素含量，其次是 GT60 和 GT47。过氧化物酶活性在叶鞘基边缘（ROC22）比其他品种更高。丙二醛含量在 GT60 中最高，其次是 ROC22 和 GT47。外切-β-1,4-葡聚糖酶/纤维二糖水解酶活性在 GT47 的边缘比 ROC22 和 GT60 的侧轴和中轴更高。轴活性呈指数增长，ROC22 从中轴边缘逐渐下降，在侧轴和中轴上低于 GT47 和 GT60。总之，成熟叶片容易脱叶，主要是松散的叶鞘，较大的叶鞘倾斜角度，离层生长期间较大的变形，早期有较大的裂缝，以及缓慢的褐变过程。纤维和木质素含量高的叶鞘表现出显著的硬度和厚度。甘蔗品种中过氧化物酶和丙二醛含量与成熟叶鞘基部的褐变过程呈正相关。
