Kakar K U, Ren X-L, Nawaz Z, Cui Z-Q, Li B, Xie G-L, Hassan M A, Ali E, Sun G-C
State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, China.
College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China.
Plant Biol (Stuttg). 2016 May;18(3):471-83. doi: 10.1111/plb.12427. Epub 2016 Jan 26.
In the present study, a consortium of two rhizobacteria Bacillus amyloliquefaciens Bk7 and Brevibacillus laterosporus B4, termed 'BB', biochemical elicitors salicylic acid and β-aminobutyric acid (SB) and their mixture (BBSB) were investigated for cold and drought stress tolerance in rice plants. After withholding water for 16 days, rice plants treated with BBSB showed 100% survival, improved seedling height (35.4 cm), shoot number (6.12), and showed minimum symptoms of chlorosis (19%), wilting (4%), necrosis (6%) and rolling of leaves. Similarly, BB inoculation enhanced plant growth and reduced overall symptoms in rice seedlings subjected to 0 ± 5 °C for 24 h. Our results imply several mechanisms underlying BB- and BBSB-elicited stress tolerance. In contrast to the control, both treatments significantly decreased leaf monodehydroascorbate (MDA) content and electrolyte leakage, and increased leaf proline and cholorophyll content. Moreover, activities of antioxidant enzymes, superoxide dismutase (SOD) and catalase (CAT) increased 3.0- and 3.6-fold, respectively. Moreover, expression of OsMYB3R-2, OsDIL, OsDREB1A and OsCDPK13 genes was significantly up-regulated, suggesting that these genes play important roles in abiotic stress tolerance of rice. In addition, bacterial strains Bk7 and B4 were able to produce high amounts of IAA and siderophores, and colonise the plant roots, while only strain Bk7 exhibited the capability to form biofilms and solubilise inorganic phosphate. This study indicates that the BB and BBSB bio-formulations can be used to confer induced systematic tolerance and improve the health of rice plants subject to chilling and drought stress.
在本研究中,对由解淀粉芽孢杆菌Bk7和类芽孢杆菌B4组成的联合菌群(称为“BB”)、生化诱导剂水杨酸和β-氨基丁酸(SB)及其混合物(BBSB)在水稻植株的耐寒和耐旱胁迫耐受性方面进行了研究。在停水16天后,用BBSB处理的水稻植株存活率达100%,幼苗高度增加(35.4厘米),分蘖数增加(6.12个),且黄化(19%)、萎蔫(4%)、坏死(6%)和叶片卷曲等症状最轻。同样,接种BB可促进水稻幼苗生长,并减轻在0±5℃处理24小时后的整体症状。我们的结果表明了BB和BBSB诱导胁迫耐受性的几种潜在机制。与对照相比,这两种处理均显著降低了叶片中单脱氢抗坏血酸(MDA)含量和电解质渗漏,并增加了叶片脯氨酸和叶绿素含量。此外,抗氧化酶超氧化物歧化酶(SOD)和过氧化氢酶(CAT)的活性分别提高了3.0倍和3.6倍。此外,OsMYB3R-2、OsDIL、OsDREB1A和OsCDPK13基因显著上调表达,表明这些基因在水稻非生物胁迫耐受性中发挥重要作用。此外,细菌菌株Bk7和B4能够产生大量吲哚-3-乙酸(IAA)和铁载体,并定殖于植物根部,而只有菌株Bk7具有形成生物膜和溶解无机磷的能力。本研究表明,BB和BBSB生物制剂可用于赋予水稻诱导系统耐受性,并改善遭受低温和干旱胁迫的水稻植株健康状况。