TY  - EJOU
AU  - Mi, Chao 
AU  - Li, Shimeng 
AU  - Yang, Xuetao 
AU  - Wang, Jinxiong 

TI  - Regulatory Mechanisms of Branch Angle in <i>Brassica rapa</i> L. in Xizang Based on RNA-seq and Targeted-Metabolome Analyses
T2  - Phyton-International Journal of Experimental Botany

PY  - 2026
VL  - 95
IS  - 8
SN  - 1851-5657

AB  - Rapeseed (<i>Brassica rapa</i> L.) is the primary oil crop in Xizang. However, its loosely branched structure hinders mechanical harvesting. Improvement in plant architecture is necessary to align with industrial development; however, research on branch angle in rapeseed is limited. The branch angle of compact plant type (S) was smaller than that of the dispersed plant type (F). RNA sequencing and targeted metabolome analyses of branch angles of both plant types were assessed at different branch sites. In the S plant type, IAA (3-Indoleacetic acid) contents were significantly higher than those in F at the five stem locations. Targeted metabolome analysis showed that IAA-glu-diME, IAA-Asp, and ICAld were significantly higher in S than in F. Compared to the F plant type, <i>PIN</i> family genes were associated with auxin transport and <i>SGR</i> family genes were significantly upregulated at the branch sites in S. The <i>LAZY1</i> expression was significantly upregulated, which may be associated with smaller branch angles. In S, a base mutation in the AuxRR core may be associated with a loss of auxin sensitivity in <i>LAZY1</i> (<i>LOC103846512</i>), whereas that in the <i>LAZY1</i> promoter increased auxin sensitivity. This study helps in understanding hormone levels in rapeseed stems and branches to develop compact plant types for superior yield and machine harvesting.
KW  - Xizang; IAA; compact type lines in <i>Brassica rapa</i> L.; branch angle; <i>LAZY1</i> promoter

DO  - 10.32604/phyton.2026.085115