The boron transporter BnaC4.BOR1;1c is critical for inflorescence development and fertility under boron limitation in Brassica napus.
The boron transporter BnaC4.BOR1;1c is critical for inflorescence development and fertility under boron limitation in Brassica napus.
复制标题
DOI：
10.1111/pce.12987
复制
发表时间：
2017-09
期刊：
影响因子：
--
通讯作者：
Quanquan Zhang;Haifei Chen;Mingliang He;Zhuqing Zhao;H. Cai;G. Ding;Lei Shi;Fangsen Xu
中科院分区：
文献类型：
--
作者：
Quanquan Zhang;Haifei Chen;Mingliang He;Zhuqing Zhao;H. Cai;G. Ding;Lei Shi;Fangsen Xu
B是植物必需的微量营养素，但B在异源四倍体油菜(Brassica Napus)体内吸收和分配的分子机制尚不清楚。在这里，我们鉴定了一个油菜B转运蛋白，BnaC4.BOR1；1c，它在茎节中表达，并参与将B分配到生殖器官。含有Bna C4.BOR1；1c启动子驱动的GUS报告基因的转基因拟南芥植株在根、茎节区和未成熟的花芽中表现出较强的GUS活性。在拟南芥野生型或bor1-1突变体中过表达Bna C4.BOR1；1c促进了野生型的生长，挽救了bor1-1突变体的表型。相反，在B高效油菜品系中，Bna C4.BOR1；1c基因的敲除减少了花器官中B的积累，最终导致严重的不育性和种子产量损失。BnaC4.BOR1；1c RNAi植株在低硼条件下表现出大量解体的柱头乳突细胞，细胞壁增厚，并伴有木质化的异常增殖，表明这种不育可能是花器官细胞壁性质改变的结果。综上所述，我们的结果表明，BnaC4.BOR1；1c是一个在根和茎节中表达的B转运蛋白基因，对花序组织的发育是必需的，这突显了它在异源四倍体油菜中与二倍体模式植物拟南芥不同的功能。
Boron (B) is an essential micronutrient for plants, but the molecular mechanisms underlying the uptake and distribution of B in allotetraploid rapeseed (Brassica napus) are unclear. Here, we identified a B transporter of rapeseed, BnaC4.BOR1;1c, which is expressed in shoot nodes and involved in distributing B to the reproductive organs. Transgenic Arabidopsis plants containing a BnaC4.BOR1;1c promoter-driven GUS reporter gene showed strong GUS activity in roots, nodal regions of the shoots and immature floral buds. Overexpressing BnaC4.BOR1;1c in Arabidopsis wild type or in bor1-1 mutants promoted wild-type growth and rescued the bor1-1 mutant phenotype. Conversely, knockdown of BnaC4.BOR1;1c in a B-efficient rapeseed line reduced B accumulation in flower organs, eventually resulting in severe sterility and seed yield loss. BnaC4.BOR1;1c RNAi plants exhibited large amounts of disintegrated stigma papilla cells with thickened cell walls accompanied by abnormal proliferation of lignification under low-B conditions, indicating that the sterility may be a result of altered cell wall properties in flower organs. Taken together, our results demonstrate that BnaC4.BOR1;1c is a AtBOR1-homologous B transporter gene expressing in both roots and shoot nodes that is essential for the developing inflorescence tissues, which highlights its diverse functions in allotetraploid rapeseed compared with diploid model plant Arabidopsis.