Chinnaswamy Appunu, Sakthivel Surya Krishna, Channappa Mahadevaiah, Ramanathan Valarmathi, Shivalingamurthy Suresha Giriyapur, Peter Swathik Clarancia, Kumar Ravinder, Kumar Raja Arun, Dhansu Pooja, Meena Mintu Ram, Raju Gomathi, Boominathan Parasuraman, Markandan Manickavasagam, Muthukrishnan Arun
Division of Crop Improvement, Indian Council of Agricultural Research-Sugarcane Breeding Institute, Coimbatore, Tamil Nadu, 641007, India.
Division of Vegetable Crops, Indian Institute of Horticultural Research, Bengaluru, Karnataka, 560089, India.
BMC Plant Biol. 2024 Dec 26;24(1):1246. doi: 10.1186/s12870-024-05932-6.
Drought is one of main critical factors that limits sugarcane productivity and juice quality in tropical regions. The unprecedented changes in climate such as monsoon failure, increase in temperature and other factors warrant the need for development of stress tolerant cultivars to sustain sugar production. Plant Nuclear factor (NF-Y) is one of the major classes of transcription factors that have a major role in plant development and abiotic stress response. In our previous studies, we found that under drought conditions, the nuclear factor NF-YB2 was highly expressed in Erianthus arundinaceus, an abiotic stress tolerant wild genus of Saccharum species. In this study, the coding sequence of NF-YB2 gene was isolated from Erianthus arundinaceus and overexpressed in sugarcane to develop drought tolerant lines. RESULTS : EaNF-YB2 overexpressing sugarcane (OE) lines had higher relative water content, chlorophyll content and photosynthetic efficiency compared to non-transgenic (NT) control. In addition, overexpressing lines had higher activity of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR), and higher proline content, lower malondialdehyde (MDA) and peroxide (HO) contents. The expression studies revealed that EaNF-YB2 expression was significantly higher in OE lines than NT control under drought stress. The OE lines had an elevated expression of abiotic stress responsive genes such as BRICK, HSP 70, DREB2, EDH45, and LEA3. The morphological analysis revealed that OE lines exhibited less wilting than NT under drought conditions.
This study provides insights into the role of the EaNF-YB2 gene in drought tolerance in sugarcane. Based on the findings of this study, the EaNF-YB2 gene can be potentially exploited to produce drought tolerant sugarcane cultivars to sustain sugarcane production under water deficit conditions.
干旱是限制热带地区甘蔗生产力和汁液品质的主要关键因素之一。季风失败、气温升高等前所未有的气候变化以及其他因素，使得有必要培育耐胁迫品种以维持蔗糖生产。植物核因子（NF-Y）是一类主要的转录因子，在植物发育和非生物胁迫响应中起主要作用。在我们之前的研究中，我们发现干旱条件下，核因子NF-YB2在甘蔗属的非生物胁迫耐受野生属斑茅中高度表达。在本研究中，从斑茅中分离出NF-YB2基因的编码序列，并在甘蔗中过表达以培育耐旱品系。
与非转基因（NT）对照相比，过表达EaNF-YB2的甘蔗（OE）品系具有更高的相对含水量、叶绿素含量和光合效率。此外，过表达品系具有更高的抗氧化酶活性，如超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、抗坏血酸过氧化物酶（APX）和谷胱甘肽还原酶（GR），脯氨酸含量更高，丙二醛（MDA）和过氧化氢（HO）含量更低。表达研究表明，在干旱胁迫下，OE品系中EaNF-YB2的表达显著高于NT对照。OE品系中诸如BRICK、HSP 70、DREB2、EDH45和LEA3等非生物胁迫响应基因的表达升高。形态学分析表明，在干旱条件下，OE品系比NT品系表现出更少的萎蔫。
本研究深入了解了EaNF-YB2基因在甘蔗耐旱性中的作用。基于本研究结果，EaNF-YB2基因有望用于培育耐旱甘蔗品种，以在水分亏缺条件下维持甘蔗生产。
