The light and dark sides of nitric oxide: multifaceted roles of nitric oxide in plant responses to light

Abstract

Light drives photosynthesis and informs plants about their surroundings. Regarded as a multifunctional signaling molecule in plants, nitric oxide (NO) has been repeatedly demonstrated to interact with light signaling cascades to control plant growth, development and metabolism. During early plant development, light-triggered NO accumulation counteracts negative regulators of photomorphogenesis and modulates the abundance of, and sensitivity to, plant hormones to promote seed germination and de-etiolation. In photosynthetically active tissues, NO is generated at distinct rates under light or dark conditions and acts at multiple target sites within chloroplasts to regulate photosynthetic reactions. Moreover, changes in NO levels in response to light stress promote plant defenses against oxidative stress under high light or ultraviolet-B radiation. Here we review the literature on the interaction of NO with the complicated light and hormonal signaling cascades controlling plant photomorphogenesis and light stress responses, focusing on the recently identified molecular partners and action mechanisms of NO in these events. We also discuss the versatile role of NO in regulating both photosynthesis and light-dependent stomatal movements, two key determinants of plant carbon gain. The regulation by light of nitrate reductase (NR) is highlighted as vital to adjust NO production in plants living under natural light conditions.

Modulation by S-nitrosoglutathione (a natural nitric oxide donor) of photosystem in Pisum sativum leaves, as revealed by chlorophyll fluorescence: Light-dependent aggravation of nitric oxide effects

“…ROS and NO could exert multiple effects on photosynthetic and mitochondrial metabolisms (5,6). The impact of ROS on photosynthesis was studied by several groups (7,8), while the studies with NO are just catching up (9). Nitric oxide (NO), can modulate various physiological processes in plants (9,10).…”

“…The impact of ROS on photosynthesis was studied by several groups (7,8), while the studies with NO are just catching up (9). Nitric oxide (NO), can modulate various physiological processes in plants (9,10). There are contrasting claims that NO can be harmful or beneficial for plant cells against stress (4,11,12).…”

Nitric Oxide Regulates Seed Germination by Integrating Multiple Signalling Pathways

“…In addition, during seed germination of different types of plants, NO signals can affect physiological responses to a variety of factors, including light, temperature, drought, and salinity [12,23,24]. Moreover, a large number of studies have emphasized that the interaction between NO and phytohormones is crucial in seed biology [25].…”