Wang Zhili, Huang Cheng, Niu Yongchao, Yung Wai-Shing, Xiao Zhixia, Wong Fuk-Ling, Huang Mingkun, Wang Xin, Man Chun-Kuen, Sze Ching-Ching, Liu Ailin, Wang Qianwen, Chen Yinglong, Liu Shuo, Wu Cunxiang, Liu Lifeng, Hou Wensheng, Han Tianfu, Li Man-Wah, Lam Hon-Ming
Centre for Soybean Research of the State Key Laboratory of Agrobiotechnology and School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.
College of Agronomy, Hunan Agricultural University, Changsha, 410128, China.
Theor Appl Genet. 2022 Dec;135(12):4507-4522. doi: 10.1007/s00122-022-04235-4. Epub 2022 Nov 24.
The genetic basis of soybean root system architecture (RSA) and the genetic relationship between shoot and RSA were revealed by integrating data from recombinant inbred population grafting and QTL mapping. Variations in root system architecture (RSA) affect the functions of roots and thus play vital roles in plant adaptations and agricultural productivity. The aim of this study was to unravel the genetic relationship between RSA traits and shoot-related traits in soybean. This study characterized RSA variability at seedling stage in a recombinant inbred population, derived from a cross between cultivated soybean C08 and wild soybean W05, and performed high-resolution quantitative trait locus (QTL) mapping. In total, 34 and 41 QTLs were detected for RSA-related and shoot-related traits, respectively, constituting eight QTL clusters. Significant QTL correspondence was found between shoot biomass and RSA-related traits, consistent with significant correlations between these phenotypes. RSA-related QTLs also overlapped with selection regions in the genome, suggesting the cultivar RSA could be a partial consequence of domestication. Using reciprocal grafting, we confirmed that shoot-derived signals affected root development and the effects were controlled by multiple loci. Meanwhile, RSA-related QTLs were found to co-localize with four soybean flowering-time loci. Consistent with the phenotypes of the parental lines of our RI population, diminishing the function of flowering controlling E1 family through RNA interference (RNAi) led to reduced root growth. This implies that the flowering time-related genes within the RSA-related QTLs are actually contributing to RSA. To conclude, this study identified the QTLs that determine RSA through controlling root growth indirectly via regulating shoot functions, and discovered superior alleles from wild soybean that could be used to improve the root structure in existing soybean cultivars.
通过整合重组自交群体嫁接和QTL定位的数据，揭示了大豆根系结构（RSA）的遗传基础以及地上部与RSA之间的遗传关系。根系结构（RSA）的变异会影响根系功能，从而在植物适应性和农业生产力中发挥至关重要的作用。本研究的目的是揭示大豆中RSA性状与地上部相关性状之间的遗传关系。本研究对一个重组自交群体在苗期的RSA变异性进行了表征，该群体源自栽培大豆C08与野生大豆W05的杂交，并进行了高分辨率数量性状位点（QTL）定位。总共分别检测到34个和41个与RSA相关和地上部相关性状的QTL，构成了8个QTL簇。在地上部生物量与RSA相关性状之间发现了显著的QTL对应关系，这与这些表型之间的显著相关性一致。与RSA相关的QTL也与基因组中的选择区域重叠，表明栽培品种的RSA可能是驯化的部分结果。通过 reciprocal grafting，我们证实了地上部衍生的信号影响根系发育，且这些影响受多个位点控制。同时，发现与RSA相关的QTL与四个大豆开花时间位点共定位。与我们RI群体亲本系的表型一致，通过RNA干扰（RNAi）削弱开花控制E1家族的功能会导致根系生长减少。这意味着RSA相关QTL内与开花时间相关的基因实际上对RSA有贡献。总之，本研究鉴定了通过调节地上部功能间接控制根系生长来决定RSA的QTL，并从野生大豆中发现了可用于改善现有大豆品种根系结构的优良等位基因。
