Background

Cellulose synthase (CESA) mutants have potential use in straw processing due to their lower cellulose content, but almost all of the mutants exhibit defective phenotypes in plant growth and development. Balancing normal plant growth with reduced cellulose content remains a challenge, as cellulose content and normal plant growth are typically negatively correlated with one another.

Result

Here, the rice (Oryza sativa) semi-dominant brittle culm (sdbc) mutant Sdbc1, which harbors a substitution (D387N) at the first conserved aspartic acid residue of OsCESA9, exhibits lower cellulose content and reduced secondary wall thickness as well as enhanced biomass enzymatic saccharification compared with the wild type (WT). Further experiments indicated that the OsCESA9^D387N mutation may compete with the wild-type OsCESA9 for interacting with OsCESA4 and OsCESA7, further forming non-functional or partially functional CSCs. The OsCESA9/OsCESA9^D387N heterozygous plants increase salt tolerance through scavenging and detoxification of ROS and indirectly affecting related gene expression. They also improve rice straw return to the field due to their brittle culms and lower cellulose content without any negative effects in grain yield and lodging.

Conclusion

Hence, OsCESA9^D387N allele can improve rice salt tolerance and provide the prospect of the rice straw for biofuels and bioproducts due to its improved enzymatic saccharification.

中文翻译：

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通过改变水稻细胞壁特性，OsCESA9中的半显性突变提高了耐盐性并有利于田间稻草的衰变特性。

背景

纤维素合酶（CESA）突变体因其纤维素含量较低而具有潜在的秸秆加工用途，但几乎所有突变体在植物生长发育中均表现出缺陷的表型。平衡正常植物生长与减少纤维素含量仍然是一个挑战，因为纤维素含量和正常植物生长通常彼此负相关。

结果

在此，水稻（Oryza sativa）半显性脆性茎秆（sdbc）突变体Sdbc 1在OsCESA9的第一个保守的天冬氨酸残基上具有取代（D387N），具有较低的纤维素含量，并降低了次生壁厚，并且增强了与野生型（WT）相比，生物质酶促糖化程度更高。进一步的实验表明，OsCESA9 ^D387N突变可能与野生型OsCESA9竞争与OsCESA4和OsCESA7相互作用，从而进一步形成无功能或部分功能的CSC。OsCESA9 / OsCESA9 ^D387N杂合植物通过清除和解毒ROS并间接影响相关基因的表达来提高耐盐性。它们还具有易碎的茎秆和较低的纤维素含量，因此可以提高稻草返回田间的产量，而对谷物产量和倒伏率没有任何负面影响。

结论

因此，OsCESA9 ^D387N等位基因由于其改善的酶促糖化作用，可以提高水稻的耐盐性，并为稻草提供生物燃料和生物制品的前景。