The Tolerance of Salinity in Rice Requires the Presence of a Functional Copy of FLN2
The Tolerance of Salinity in Rice Requires the Presence of a Functional Copy of FLN2
复制标题
水稻的耐盐性需要 FLN2 的功能副本的存在
DOI：
10.3390/biom10010017
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发表时间：
2020-01-01
期刊：
影响因子：
5.5
通讯作者：
Qian, Qian
中科院分区：
文献类型：
--
作者：
Chen, Guang;Hu, Jiang;Qian, Qian
一组乙烷-甲基-磺酸盐诱变的粳稻品系在盐的存在下生长，以鉴定耐盐性表达所需的基因。一个高度不耐受的选择被证明在FLN 2（一个编码果糖激酶样蛋白2的基因）中存在突变。野生型水稻暴露于盐度上调FLN 2，而CRISPR/Cas9产生的FLN 2敲除系对胁迫高度敏感。核酮糖1，5-二磷酸羧化酶/加氧酶活性和蔗糖合成组分编码基因产生的转录本丰度在敲除系中均低于野生型植物的叶片，而叶片和根的蔗糖含量分别显著增加和减少。在FLN 2敲除植物中，糖分配到根中受损，这一点通过观察到参与碳运输的几个基因在叶和叶鞘中均下调而得到证实。蔗糖合成酶、酸性转化酶和中性转化酶的活性在基因敲除植物的根中明显低于野生型植物，特别是当植物暴露于盐胁迫时。FLN 2基因敲除植物表现出的耐盐性受损可能是支持生长所需的同化物供应不足的结果，这是一个可以通过提供外源蔗糖供应来纠正的问题。结论是，FLN 2，由于其对糖代谢的影响，在水稻幼苗生长和植物对盐胁迫的反应中是重要的。
A panel of ethane-methyl-sulfonate-mutagenized japonica rice lines was grown in the presence of salinity in order to identify genes required for the expression of salinity tolerance. A highly nontolerant selection proved to harbor a mutation in FLN2, a gene which encodes fructokinase-like protein2. Exposure of wild-type rice to salinity up-regulated FLN2, while a CRISPR/Cas9-generated FLN2 knockout line was hypersensitive to the stress. Both ribulose 1,5-bisphosphate carboxylase/oxygenase activity and the abundance of the transcript generated by a number of genes encoding components of sucrose synthesis were lower in the knockout line than in wild-type plants’ leaves, while the sucrose contents of the leaf and root were, respectively, markedly increased and decreased. That sugar partitioning to the roots was impaired in FLN2 knockout plants was confirmed by the observation that several genes involved in carbon transport were down-regulated in both the leaf and in the leaf sheath. The levels of sucrose synthase, acid invertase, and neutral invertase activity were distinctly lower in the knockout plants’ roots than in those of wild-type plants, particularly when the plants were exposed to salinity stress. The compromised salinity tolerance exhibited by the FLN2 knockout plants was likely a consequence of an inadequate supply of the assimilate required to support growth, a problem which was rectifiable by providing an exogenous supply of sucrose. The conclusion was that FLN2, on account of its influence over sugar metabolism, is important in the context of seedling growth and the rice plant’s response to salinity stress.