Physio-biochemical Responses of In Vitro Cooking Banana Musa paradisiaca cv Lang towards Polyethylene Glycol (PEG)Induced Drought Stress

Abstract

Musa paradisiaca cv Lang belongs to the cooking banana group, and it has high potential to be used in banana chips production. Like other cultivars, M. paradisiaca cv Lang is susceptible to drought, which could affect banana growth and productivity. Therefore, in this study we aimed to determine the physiological and biochemical changes of in vitro Lang banana plantlets grown under drought stress. To achieve the objective, polyethylene glycol (PEG) was added into the culture media to induce drought condition. The physio-biochemical data were captured by determining root and leaves number, root length, total chlorophyll content, total protein content, and antioxidant enzymes activities. Overall, decrement of roots length and chlorophyll (Chl) content was displayed by the plantlets exposed to 1%, 2%, 3%, 4%, and 5% (w/v) of PEG after three weeks of exposure. However, the proline content, total soluble protein content, and antioxidant capacity in leaves and roots were varied in response to different concentrations of PEG. Plantlets supplemented with 2% (w/v) of PEG recorded the highest proline content in leaf (12.66±0.38 μmole/g FW) while the total soluble protein content was recorded the highest in roots of 5% (w/v) of PEG-treated plantlets (30.65±1.07 mg/g FW). The highest catalase (CAT) and guaiacol peroxidase (POD) activities were found in the leaf of 1% (w/v) (10.69±5.06 µmol/min/mg protein) and 4% (w/v) (0.079±0.03 µmol/min/mg protein) of PEG-treated plantlets. Meanwhile, the highest ascorbate peroxidase (APX) activity was found in the roots of 3% (w/v) of PEG-treated plantlets (16.69±0.5 µmol/min/mg protein). Therefore, these data show the capability of Lang banana to develop physio-biochemical mechanisms in response to different levels of drought stress, in which these data can be used in the future to develop drought tolerant Lang banana.