DOI：org/10.1111/tpj.17200

发表期刊：The Plant Journal

链接：http://doi.org/10.1111/tpj.17200

作者：Xiaoheng Xu†, Yueyang Liang†, Guangyan Feng, Shunfeng Li, Zhongfu Yang, Gang Nie, Linkai Huang*, Xinquan Zhang*

Abstract：Tiller number is a crucial determinant that significantlyinfluencestheproductivityand reproductive capacityof forage.The regenerationpotential,biomass production, and seed yield of perennial foragespeciesarehighly reliant on the development oftillering.Strigolactones(SLs)arerecently discoveredcarotenoid-derivedphytohormonesthat play a crucial role in the regulation of tillering in annual crops. However, the modulation of tiller growth in perennial forage by SLs remains insufficiently investigated. In this study, weidentifiedtwo alleles of the SLs biosynthesis gene,DgCCD7^AandDgCCD7^D, whichencodeCAROTENOID CLEAVAGE DIOXYGENASE 7(CCD7),fromtwo distinct subspeciesoforchardgrass(Dactylis glomerata)exhibitingcontrasting tillering phenotype and SLs content.The functionality of theDgCCD7^Aallele derived from high-tillering phenotypicorchardgrass was found to be diminished compared to that ofDgCCD7^Dfrom the low-tillering type in rescuing the increased branching phenotype ofCCD7-defective mutants inArabidopsisand rice (Oryza sativa).Notably, the introduction ofDgCCD7^Ain rice resulted in an increase in tiller number without significantly compromising grain yield.Moreover,we demonstrated that the L309P variation in DgCCD7^Aas a rare natural variantexclusively found inorchardgrass.Our findings revealedthatDgCCD7^A, a rare favorable natural variation ofCCD7inorchardgrass,holds significantpotentialfor breeding application inimprovingthe plant architecture of perennial forage and crops.

Keywords:Dactylis glomerata,tiller number, branch number,CCD7,strigolactones