Open Access

ARTICLE

Regulatory Mechanisms of Branch Angle in Brassica rapa L. in Xizang Based on RNA-seq and Targeted-Metabolome Analyses

Chao Mi^1,*, Shimeng Li¹, Xuetao Yang², Jinxiong Wang^1,*

1 Agricultural Research Institute, Xizang Academy of Agriculture and Animal Husbandry Sciences, Lhasa, China
2 Xizang Academy of Agriculture and Animal Husbandry Sciences, Lhasa, China

* Corresponding Authors: Chao Mi. Email: ; Jinxiong Wang. Email:

(This article belongs to the Special Issue: Plant Growth Regulators (PGRs) and Plant Stress)

Phyton-International Journal of Experimental Botany 2026, 95(8), 14 https://doi.org/10.32604/phyton.2026.085115

Received 06 May 2026; Accepted 27 July 2026; Issue published 28 August 2026

Abstract

Rapeseed (Brassica rapa 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, PIN family genes were associated with auxin transport and SGR family genes were significantly upregulated at the branch sites in S. The LAZY1 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 LAZY1 (LOC103846512), whereas that in the LAZY1 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.

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Keywords

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Supplementary Material

Supplementary Material File

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