Title: Nitric oxide exposure impacts on morphology and auxin transport of Oryza sativa under arsenic stress
Nitric Oxide (NO), a signal molecule plays vital role to provide tolerance to abiotic stress in plants by interplay with reactive oxygen species, and thus promoting their growth and development. Arsenic (As) is a toxic metalloid and its contamination found in crop plants, mainly rice which is an important diet for millions of people. In this study 7 days old hydroponically grown rice seedlings were exposed to As(III) (150 μM), NO (100 μM), As(III)+NO for 48 h and control (without metal). We observed NO-mediated alteration on physiological, biochemical and stress-related parameters along with auxin transporter PIN genes (OsPIN1a, OsPIN1b, OsPIN1c, OsPIN1d, OsPIN2, OsPIN5a, OsPIN5c, OsPIN8, OsPIN9, OsPIN10b), expression under As stress. As exposure reduced the overall plant growth, formation of lateral roots, chlorophyll and protein content and enhanced the oxidative stress by increasing the level of antioxidant enzymes (SOD, CAT, APX, GR), and stress-related parameters (cysteine, proline, MDA, H2O2). Supplementation of NO along with As reduced the accumulation of As in rice seedlings, improved plant growth, and lateral root formation, increased chlorophyll and protein content and diminished the level of antioxidant enzymes and stress-related parameters by reducing ROS generation. The addition of NO also up-regulates the gene expression of auxin transporters. Overall, NO reduced the toxicity of As using various mechanisms and provide tolerance to its stress in rice seedlings.
Audience Take Away Notes :
- Plants have the ability to adapt themselves under stressed (heavy metals such as arsenic) conditions through reprogramming their growth and development. Understanding the mechanisms regulating overall growth of stressed plant is an important issue for plant and environmental biology research.
- This study will be helpful for Plant/Environmental Biotechnology researchers. Since, most of the developmental processes in plants are govern by the hormonal actions, the present study will benefit in future work to provide more insight about the molecular mechanisms of NO in modulating plant As tolerance through hormonal interaction network, and As induced morphological responses in crop plants.
- These experimental studies could facilitate in future to produce As tolerant plants. This will help to confront the As toxicity in the environment and to reduce the challenges in way of agriculture productivity and global food demands.
- It will help to reduce the toxicity of As in crop plants through generation of As tolerant transgenic plants.
- A systematic understanding of genes involved in As tolerance will enable breeders to improve the plant growth leading to generation of crop with high yields and better tolerance to As by using genetic manipulation.
- NO could be used to alleviate the toxicity of As in crop plants in edible portion. Its entry into food chain could be reduced/eliminated thus associated disease like skin lesions and cancer in humans could be prevented.
- Phytotoxicity could be reduced as well yield will be enhanced by overexpressing the As tolerant genes.