Bacterial endophytes from arid land plants regulate endogenous hormone content and promote growth in crop plants: an example of Sphingomonas sp. and Serratia marcescens

Journal of Plant Interactions

Ah-Yeong Kim¹  Muhammad Aaqil Khan¹  Raheem Shahzad¹  Sajjad Asaf¹  Muhammad Waqas¹  Sang-Mo Kang¹  In-Jung Lee¹  Abdul Latif Khan² 

[1] School of Applied Biosciences, Kyungpook National University;UoN Chair of Oman's Medicinal Plants and Marine Natural Products, University of Nizwa;

关键词: Endophytes;    soybean;    phytohormones;    agronomic crops;    hormonal regulation;    plant growth characteristics;    environmentally friendly agriculture;   

DOI  :  10.1080/17429145.2016.1274060

来源: DOAJ

【 摘 要 】

The objective of the present study was to determine the potential plant growth-promoting action of bacterial endophytes isolated from arid land-dwelling plants under normal conditions. Overall, five bacterial endophytes LK11 (Sphingomonas sp. LK11), TP5 (Bacillus subtilis), MPB5.3 (B. subtilis subsp. Subtilis), S9 (B. subtilis subsp. Subtilis), and TP1 (Serratia marcescens) were evaluated based on morphological characteristics after isolation and purification. Phytohormonal analysis of these endophytes predicted indole acetic acid (IAA) production 12.31 ± 0.45 , 6.8 ± 0.59, and 10.5 ± 1.02 μM/mL in the culture broths of LK11, MPB5.3, and TP1, respectively. Under controlled greenhouse conditions, these endophytes were inoculated into soybean, and their growth-promoting characteristics were compared with those of non-phytohormone-producing endophytes. In terms of plant growth promotion, among IAA-producing endophytes, LK11 and TP1 greatly improved physiological characteristics such as shoot/root length, fresh/dry weight, and chlorophyll contents. However, the non-phytohormone-producing endophytes TP5 and S9 did not show a growth-promoting effect. Based on these results, plants inoculated with LK11 and TP1 along with a control were subjected to endogenous hormonal analysis and showed a significant increase in abscisic acid (457.30–398.55 vs. 205.93 ng/g D.W.) and a decrease in jasmonic acid content (50.07–85.07 vs. 93.90 ng/g D.W.), respectively. Total gibberellin content was found to significantly increase in endophyte-inoculated plants (155.43–146.94 ng/g D.W.) as compared to that in controls (113.76 ng/g D.W.). In summary, bacterial endophytes might be used to enhance crop plant physiological characteristics isolated from arid land-inhabiting plants under normal conditions.

【 授权许可】

Unknown