Low-boron tolerance strategies involving the pectin-mediated cell wall mechanical properties in Brassica napus
Low-boron tolerance strategies involving the pectin-mediated cell wall mechanical properties in Brassica napus
复制标题
涉及甘蓝型油菜果胶介导的细胞壁机械特性的低硼耐受策略
DOI：
10.1093/pcp/pcx130
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发表时间：
2017
影响因子：
4.9
通讯作者：
Fangsen Xu
中科院分区：
文献类型：
--
作者：
Ting Zhou;Yingpeng Hua;Baocai Zhang;Xiuqin Zhang;Yihua Zhou;Guangda Ding;Lei Shi;Fangsen Xu
硼（B）是植物生长发育所必需的微量营养元素。油菜（Brassica napus L.）是一种主要的油料作物，它非常容易受到B缺乏的影响。油菜基因型对低硼胁迫的耐受性存在显著差异，但其内在机制仍不清楚，特别是在单细胞水平上。在这里，我们提供了新的见解果胶介导的细胞壁（CW）的机械性能牵连的差异耐低B油菜基因型。在B缺乏条件下，低B敏感基因型“W 10”的悬浮细胞比低B耐受基因型“QY 10”的悬浮细胞表现出更严重的形态变形、更低的存活率和更易破裂的CW。原子力显微镜检测到细胞破裂是由于CW机械强度减弱所致，在0.25和0.10 μM B条件下，“QY 10”的CW机械强度分别降低了13.6%和17.4%，而“W 10”的CW机械强度分别降低了29.0%和30.4%.去除果胶后，“QY 10”和“W10”之间的机械强度差异减小。此外，在B缺乏条件下，W10的果胶含量显著高于QY 10，且具有更多的鼠李糖半乳糖醛酸聚糖II（RG-II）单体，果胶生物合成相关基因的mRNA丰度也显著高于QY 10。‘W10’原生质体CW再生比‘QY 10’困难。综合以上结果，我们可以得出结论：果胶赋予的CW机械性质的变化在调节油菜对低硼胁迫的单细胞和植株水平的差异基因型耐受性中起着关键作用，这可以潜在地用作耐低硼油菜育种的选择性状。
Boron (B) is an essential micronutrient for the growth and development of plants. Oilseed rape (Brassica napus L.) is a staple oleaginous crop, which is greatly susceptible to B deficiency. Significant differences in tolerance of low-B stresses are observed in rapeseed genotypes, but the underlying mechanism remains unclear, particularly at the single-cell level. Here we provide novel insights into pectin-mediated cell wall (CW) mechanical properties implicated in the differential tolerance of low B in rapeseed genotypes. Under B deficiency, suspension cells of the low-B-sensitive genotype 'W10' showed more severely deformed morphology, lower viabilities and a more easily ruptured CW than those of the low-B-tolerant genotype 'QY10'. Cell rupture was attributed to the weakened CW mechanical strength detected by atomic force microscopy; the CW mechanical strength of 'QY10' was reduced by 13.6 and 17.4%, whereas that of 'W10' was reduced by 29.0 and 30.4% under 0.25 and 0.10 μM B conditions, respectively. The mechanical strength differences between 'QY10' and 'W10' were diminished after the removal of pectin. Further, 'W10' exhibited significantly higher pectin concentrations with much more rhamnogalacturonan II (RG-II) monomer, and also presented obviously higher mRNA abundances of pectin biosynthesis-related genes than 'QY10' under B deficiency. CW regeneration was more difficult for protoplasts of 'W10' than for those of 'QY10'. Taking the results together, we conclude that the variations in pectin-endowed CW mechanical properties play key roles in modulating the differential genotypic tolerance of rapeseed to low-B stresses at both the single-cell and the plant level, and this can potentially be used as a selection trait for low-B-tolerant rapeseed breeding.