Proteome in regrowth cycles of sugarcane: Absence of proteins to tolerate adverse growth conditions may be related to reduced agricultural productivity

ABSTRACT. One of the main objectives of sugarcane plantations is to increase their longevity without decreasing agricultural productivity. In the present study, we analyzed the proteome of the axillary buds of ‘RB966928’ to investigate possible changes in the number of proteins at different cutting stages. Using tryptic digestion followed by ultra-performance liquid chromatography coupled with high-resolution time-of-flight mass spectrometry, 122 proteins were identified from the proteome of the axillary buds of ‘RB966928’. Of the 122, respectively 97 and 95 proteins were detected at the first and fifth cutting stages, of which 27 and 25 proteins were unique to the respective stage. Proteins that prevent the misfolding of polypeptides generated under stress were exclusively detected at the first cutting stage. Meanwhile, proteins associated with stress responses and disease resistance were exclusively detected at the fifth cutting stage. The present proteomic analysis in the regrowth cycles and axillary bud development of ‘RB966928’ significantly advanced our understanding of the biological processes linked to the reduction of agricultural productivity of sugarcane with the advancement of cutting age. Absence of proteins to tolerate adverse growth conditions at the fifth cutting stage may be related to reduced agricultural productivity, in addition to environmental stress, soil compaction, nutrient availability, cultural practices, and pests or pathogen attacks at different phenological stages of crops.

摘要：甘蔗种植园的核心目标之一，是在不降低农业生产力的前提下延长种植寿命。本研究对‘RB966928’品种甘蔗的腋芽（axillary buds）蛋白质组（proteome）进行分析，以探究不同砍蔗阶段的蛋白质数量变化情况。本研究采用胰蛋白酶消化（tryptic digestion）结合超高效液相色谱（ultra-performance liquid chromatography）-高分辨率飞行时间质谱（high-resolution time-of-flight mass spectrometry）联用技术，从‘RB966928’腋芽的蛋白质组中共鉴定出122种蛋白质。在这122种蛋白质中，分别有97种和95种在首次砍蔗阶段和第五次砍蔗阶段被检出，其中27种和25种为对应阶段所特有。可防止胁迫环境下产生的多肽发生错误折叠的蛋白质，仅在首次砍蔗阶段被检出。与此同时，与胁迫响应及抗病性相关的蛋白质仅在第五次砍蔗阶段被检出。本研究针对‘RB966928’的再生周期与腋芽发育开展的蛋白质组学分析，极大地加深了我们对甘蔗随砍蔗次数增加导致农业生产力下降相关生物学过程的认知。第五次砍蔗阶段缺乏耐受不良生长条件的蛋白质，可能与农业生产力下降相关；而作物不同物候期面临的环境胁迫、土壤板结、养分有效性、栽培措施以及病虫害侵袭，同样会对生产力造成影响。