Effects of Melatonin on Root Growth and Drought Tolerance of Maize Seedlings

doi:10.13560/j.cnki.biotech.bull.1985.2020-0575

Abstract

Abstract:

Melatonin（N-acetyl-5-methoxy-tryptamine）,an indoleamine neurohormone widely existing in organism,involves in many physiological and biochemical processes of plants. Recent studies understand that melatonin application may improve plant stress tolerance at varied level;however,the specific underlying mechanisms are still not fully understood. The current study was carried out to investigate the effect of melatonin on maize root system and drought tolerance via 2 applications of melatonin. Firs,the method of hydroponic root maize and irrigating melatonin were used to analyze the root system and growth status of maize seedlings. The results showed that the application of melatonin significantly improved a variety of maize seedling root parameters,including root length,root surface area,root volume,number of lateral roots,etc. Secondly,the method of melatonin-soaked seeds in pot was used to determine the relative water content of leaves,photosynthesis,antioxidant enzyme activity,and above-ground biomass. The results showed that under drought stress,the method of melatonin-soaked seed improved plant photosynthesis rate,stomatal conductance and transpiration rate,enhanced antioxidant enzyme activity,and reduced reactive oxygen species and malondialdehyde content. Our current findings hereby confirmed the beneficial effects of melatonin application in enhancing maize drought tolerance by promoting root growth,reducing oxidative damages,eliminating photosynthetic inhibition,and improving plant water status.

Key words: melatonin, root system, antioxidant, photosynthesis, drought tolerance

MA Xu-hui, CHEN Ru-mei, LIU Xiao-qing, ZHAO Jun, ZHANG Xia. Effects of Melatonin on Root Growth and Drought Tolerance of Maize Seedlings[J]. Biotechnology Bulletin, 2021, 37(2): 1-14.

Figures/Tables 9

References 51

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分类	特征	缩写	单位	描述
主根	主根长度	PAL	cm	主根（包括主根上的侧根）长度
	主根表面积	PSA	cm²	主根（包括主根上的侧根）表面积
	主根体积	PRV	cm³	主根（包括主根上的侧根）体积
	主根长度	PRL	cm	主根（不包括主根上的侧根）长度
	侧根数目	LRN_PR	branch	主根上侧根的数目
种子根	种子根的长度	SAL	cm	种子根（包括种子根上的侧根）的长度
	种子根的表面积	SSA	cm²	种子根（包括种子根上的侧根）的表面积
	种子根的体积	SRV	cm³	种子根（包括种子根上的侧根）的体积
总根	总根长	TRL	cm	整个根系的长度
	总根表面积	TSA	cm²	整个根系的表面积
	总根体积	TRV	cm³	整个根系的体积

分类	特征	缩写	单位	描述
主根	主根长度	PAL	cm	主根（包括主根上的侧根）长度
	主根表面积	PSA	cm²	主根（包括主根上的侧根）表面积
	主根体积	PRV	cm³	主根（包括主根上的侧根）体积
	主根长度	PRL	cm	主根（不包括主根上的侧根）长度
	侧根数目	LRN_PR	branch	主根上侧根的数目
种子根	种子根的长度	SAL	cm	种子根（包括种子根上的侧根）的长度
	种子根的表面积	SSA	cm²	种子根（包括种子根上的侧根）的表面积
	种子根的体积	SRV	cm³	种子根（包括种子根上的侧根）的体积
总根	总根长	TRL	cm	整个根系的长度
	总根表面积	TSA	cm²	整个根系的表面积
	总根体积	TRV	cm³	整个根系的体积

分类	特征	0 μmol/L		1 μmol/L		Significance
分类	特征	Mean	SD	Mean	SD	Significance
总根	TRL	150.375	32.656	178.512	35.414	**
	TSA	27.414	4.482	37.812	11.272	**
	TRV	0.564	0.096	0.593	0.100	***
主根	PAL	64.432	11.777	88.796	16.124	**
	PRL	23.265	0.959	28.709	0.962	****
	PSA	8.557	1.333	9.053	1.353	***
	PRV	0.348	0.487	0.370	0.463	****
	LRNPR	207	21.818	239	16.244	****
种子根	SAL	85.942	20.635	89.716	25.746	**
	SSA	18.857	3.694	28.759	2.878	***
	SRV	0.216	0.255	0.223	0.192	*

分类	特征	0 μmol/L		1 μmol/L		Significance
分类	特征	Mean	SD	Mean	SD	Significance
总根	TRL	150.375	32.656	178.512	35.414	**
	TSA	27.414	4.482	37.812	11.272	**
	TRV	0.564	0.096	0.593	0.100	***
主根	PAL	64.432	11.777	88.796	16.124	**
	PRL	23.265	0.959	28.709	0.962	****
	PSA	8.557	1.333	9.053	1.353	***
	PRV	0.348	0.487	0.370	0.463	****
	LRNPR	207	21.818	239	16.244	****
种子根	SAL	85.942	20.635	89.716	25.746	**
	SSA	18.857	3.694	28.759	2.878	***
	SRV	0.216	0.255	0.223	0.192	*

分类	特征	0 μmol/L		1 μmol/L		Significance
分类	特征	Mean	SD	Mean	SD	Significance
总根	TRL	105.7	20.737	132.2	9.196	****
	TSA	15.81	4.531	25.82	3.389	***
	TRV	0.332	0.058	0.469	0.06	***
主根	PAL	53.954	7.444	61.309	11.265	****
	PRL	18.267	1.989	21.062	2.677	****
	PSA	7.155	1.142	8.162	0.933	*
	PRV	0.159	0.013	0.312	0.014	**
	LRNPR	119	18.788	132	24.615	**
种子根	SAL	51.746	21.368	70.891	15.744	***
	SSA	8.655	4.477	17.658	5.169	***
	SRV	0.123	0.266	0.158	0.187	**