外源独脚金内酯对枳幼苗茎增粗生长的影响

doi:10.16420/j.issn.0513-353x.2024-0528

摘要/Abstract

摘要：

对枳幼苗施加不同浓度（0、10、20、30 μmol · L^-1）的外源独脚金内酯类似物GR24，测定生长指标、解剖结构和生理生化等变化，结合实时荧光定量PCR技术分析相关调控基因的表达，全面评估独脚金内酯对枳幼苗茎增粗生长的影响。研究发现枳幼苗茎的增粗生长和GR24浓度相关，只有20 μmol · L^-1处理显著促进茎的增粗生长，主要表现为木质部宽度增加，次生细胞壁增厚及木质素、纤维素和半纤维素含量成分的积累，同时茎中内源激素独脚金内酯、生长素和赤霉素含量也显著增加。定量PCR分析表明，20 μmol · L^-1GR24显著上调了生长素响应基因（ARF5）、木质部相关基因（KNAT1、STM、CAD）及形成层特异性基因（WOX4）的表达。研究结果表明20 μmol · L^-1 GR24是通过促进次生木质部细胞增加和增强木质化过程，以及诱导生长相关激素增加而显著促进枳幼苗茎的增粗。

关键词: 柑橘, 枳, 独脚金内酯, 次生生长, 相关基因表达

Abstract:

Applying varying concentrations of strigolactones（SLs）analogue GR24（0，10，20，30 μmol · L^-1），growth，anatomical structures，and physiological-biochemical changes were assessed，along with the analysis of gene expression via Quantitative Real-time PCR. The result indicated that stem thickening growth was concentration-dependent，only with the 20 μmol · L^-1 treatment significantly enhanced it. It was characterized by increased xylem width，the thickness of secondary cell wall thickening，the content of lignin，cellulose，and hemicellulos. The level of endogenous hormones，including SLs，auxin and gibberellins，also increased. qRT-PCR revealed significantly upregulated expression of auxin-responsive genes（ARF5），xylem-related genes（KNAT1，STM，CAD），and cambium-specific genes （WOX4），indicating that the 20 μmol · L^-1 GR24 treatment enhanced thickening by promoting secondary xylem cell proliferation and lignification，and inducing hormone increases.

Key words: citrus, Poncirus trifoliata, strigolactones, secondary growth, expression of related genes

周天, 吕帅丽, 韩晗, 李雨佳, 刘海强, 刘永忠. 外源独脚金内酯对枳幼苗茎增粗生长的影响[J]. 园艺学报, 2025, 52(7): 1843-1854.

ZHOU Tian, LÜ Shuaili, HAN Han, LI Yujia, LIU Haiqiang, and LIU Yongzhong. Effect of Exogenous Strigolactones on the Secondary Growth of Poncirus trifoliata Seedlings Stem[J]. Acta Horticulturae Sinica, 2025, 52(7): 1843-1854.

图/表 9

图1 不同浓度GR24对枳幼苗的地径和苗高的影响同一时间，不同小写字母表示在 P ≤ 0.05 水平处理间差异显著。下同

Fig. 1 Effect of different concentrations of GR24 on Poncirus trifoliata seedlings ground diameter and plant height Different lowercase letters at the same time indicate significant difference at P ≤ 0.05. The same in the following

表1 枳中激素和次生生长相关基因及其引物

Table 1 Hormones-related and secondary growth-related genes in Poncirus trifoliata and their primer sequences

基因功能归类 Category of gene function	基因名称 Gene name	序列ID Sequence ID	引物序列Primer sequence（5′-3′）
基因功能归类 Category of gene function	基因名称 Gene name	序列ID Sequence ID	正向引物 Forward primer	反向引物 Reverse primer
独脚金内酯相关 SLs-related	MAX1	Pt1g003810	TTGGGATACCTGTATGGA	GAGGGAATGCTTCTGTTT
	MAX2	Pt2g005380	ACCAACTGTCCGAAACTGA	AACGAGCCTACGACACCC
	IPA1	Pt3g040320	GGCGGAGATAACAAGCAC	CACCAGAACGGGAGAAAA
生长素相关 IAA-related	ARF5	Pt5g002170	TGGCACATCTTCGAGTAA	ATCGCAGAGCATAGTTCA
	ATHB8	Pt1g004770	ATGAGGGATGGTCTATGTT	AGAAGTATTGCTGGAGGC
	PIN1	Pt1g010310	AGAGGTGCCAGGTTGCTT	TTGATGGGCGTGGAGTTG
赤霉素相关 GA-related	SLR1	Pt6g004680	TTACGGTGGCGGTAGTGG	TTGTGGGTACGCAGCAGA
赤霉素相关 GA-related	DELLA	Pt2g018850	GCGGGTTTGGGTTTAGAT	GCCGATGATAGGCTCAGATA
木质部相关 Xylem-related	KNAT1	Pt5g011400	AGCCAAGATCATCTCCCA	TCGTAATAAGCCTCCATAA
	STM	Pt2g013810	CACTTCCCTCGCCTCTTG	CTGTCGGGCTTCCTTTGG
	CAD	Pt8g003710	GGGTTCTCGTTGGTTGTT	CTCCAGAGGGTGATTTGC
韧皮部相关 Phloem-related	NEN1/2	Pt3g006130	ATTGACTCGTTGGCATTG	CACATCTCCCACCTGTTC
韧皮部相关 Phloem-related	NEN4	Pt7g000360	AGTTCGGAGCAATCGTAG	ATATTATGCCCTGCCCAC
形成层相关 Cambium-related	OPS	Pt6g013590	GACACTGGGTCAGCGAGAT	TAGCAGGAGACACCTTAGCA
	WOX4	Pt5g004640	CTCACGCTTGGCTGTAAACG	GTTCGCATTCCTCCCCTGTA
	WOX14	Pt7g020570	TCAGTGCCAGACAGAGGT	AGGGAGGTTGCGTAAGTG
	KNAT6	Pt4g006750	CCGATGAGTTACTGTCTGCT	CTCCTACCTTCTGGCAAT
	BES1	Pt5g003460	AGGGCTCAGGGAAACTAT	ATGATGGAACTGGGCTTG

图2 不同浓度GR24处理对枳幼苗茎基解剖结构的影响红色：木质化；绿色：非木质化。Pi：髓；Xy：木质部；Ca：形成层；Ph：韧皮部

Fig. 2 Effect of different concentrations of GR24 on anatomical structure of the base stem of Poncirus trifoliata seedlings Red：Lignification；Green：Non lignification. Pi：Pith；Xy：Xylem；Ca：Cambium；Ph：Phloem

图3 不同浓度GR24处理对枳幼苗茎基木质部、形成层和韧皮部宽度的影响

Fig. 3 Effect of different concentrations of GR24 on the thickness of xylem，cambium and phloem of the base stem of Poncirus trifoliata seedlings

图 4 不同浓度GR24处理对枳幼苗茎中的次生细胞壁厚度的影响 A ~ D是独脚金内酯处理下茎基的木质部纤维电镜；E ~ H是A ~ D中方框区域的放大视图

Fig. 4 Effect of different concentrations of GR24 on the thickness of secondary xylem cell wall in the stem of Poncirus trifoliata seedlings A-D：TEM of xylem fibers in the base stem of plant with GR24 treatments；E-H：Higher magniffcation views of the areas in boxes in A-D

图5 不同浓度GR24处理对枳幼苗茎中的次生细胞壁厚度以及木质素含量、纤维素含量和半纤维素含量的影响

Fig. 5 Effect of different concentrations of GR24 on the thickness of secondary xylem cell wall，lignin contents，cellulose content，hemicellulose content in the stem of Poncirus trifoliata seedlings

图6 20 μmol · L-1 GR24处理对枳幼苗茎中的内源激素含量的影响 t测验，* 表示处理和对照差异显著（P ≤ 0.05）。下同

Fig. 6 Effect of 20 μmol · L-1 GR24 on endogenous hormone contents in Poncirus trifoliata seedlings stems t-test，asterisk（*）means signiffcant difference between GR24 treatment and control at P ≤ 0.05. The same below

图7 20 μmol · L-1 GR24处理对枳幼苗茎干激素相关基因表达的影响

Fig. 7 Effect of 20 μmol · L-1 GR24 on the transcript levels of hormone-related genes in Poncirus trifoliata seedlings stems

图8 20 μmol · L-1 GR24处理对枳幼苗茎干次生生长相关基因表达的影响

Fig. 8 Effect of 20 μmol · L-1 GR24 on the transcript levels of secondary growth-related gened in Poncirus trifoliata seedlings stems

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