Seed priming with light quality and Cyperus rotundus L. extract modulate the germination and initial growth of Moringa oleifera Lam. seedlings

Abstract

Improving plant germination is essential to guarantee better quality seedlings. Thus, this research aimed to evaluate whether the seed priming with light quality (LIQ) and the aqueous extract of Cyperus rotundus (AEC) tuber could modulate the germination and initial growth of Moringa oleifera L. seedlings. The experimental design was a completely randomized in the 4x4 factorial scheme, composed of four LIQ conditions (white, blue, red, and distant red light) and four AEC concentrations (0, 25, 50 and 100%). Seed priming with red light reduced the average emergence time, while blue, red, and extreme red lights associated with 50% of aqueous extract of C. rotundus increased shoot initial length and photosynthetic pigment accumulation. Seed priming with blue light resulted in seedlings with a shorter final shoot length. However, application of 100% of aqueous extract of C. rotundus reversed this. The white light in combination with concentrations of 50 and 100% of AEC promoted a higher relative shoot growth rate of seedlings. The research revealed that seed priming with light quality and aqueous extracts of C. rotundus tubers modulates the germination and initial growth of M. oleifera seedlings. More work needs to be done to determine the responsible compounds in AEC that is responsible for priming growth as phytohormones.

Seed Priming with Glass Waste Microparticles and Red Light Irradiation Mitigates Thermal and Water Stresses in Seedlings of Moringa oleifera

“…Therefore, as already stressed by [ 2 ], the photomorphogenesis of Moringa oleifera is mediated by the interaction between light, water, and phytohormones during SP, reinforcing the idea that RL has a synergistic effect on the action of SiMPs since irradiation with RL activates phyB, whose activity reduces the levels of abscisic acid (ABA), a germination repressor, and increases the levels of gibberellic acid (GA), which stimulates germination [ 33 ] and could have generated a memory effect when the seeds were dehydrated. This information is essential for sustainably managing agroecosystems cultivated with M. oleifera , especially in semi-arid regions where thermal and water stresses are frequent.…”

“…This mitigation occurs as the SiMPs cross cell wall barriers and, when in contact with plant cells, are captured by plasmodesmata pathways and translocated by apoplastic and/or symplastic pathways [ 19 , 23 ], reducing lipid peroxidation by decreasing the H 2 O 2 levels, which restores the redox balance and mitigates oxidative stress [ 25 ]. In addition, RL could have potentiated the effect of SiMPs since RL irradiation activates the phyA, phyB, phyC, phyD, and phyE phytochromes responsible for light capture and modulation, gene expression, and the transduction of signals related to growth regulation, plant development, metabolic activities, and responses to heat and water stress [ 2 , 27 ].…”

“…However, the increase in production has to occur with the lowest possible impact on natural resources in order to meet one of the priority goals of the 2030 Agenda for Sustainable Development [ 1 ]. From this perspective, one alternative to increase food production and reduce the impacts of agriculture on agroecosystems is growing plants with the potential for multiple uses and genotypic and phenotypic plasticity for different cultivation environments [ 2 ].…”

“…This scenario highlights the desire for technologies that can mitigate the effects of abiotic stresses on M. oleifera . In that regard, seed priming emerges as a promising alternative [ 2 ] that consists of soaking seeds in stress-mitigating solutions, e.g., silicon microparticle sources (SiMPs), with verified positive results in stress management in other crops, because the silicon is deposited in the endoplasmic reticulum, cell walls and intercellular spaces as hydrated amorphous silica, in addition to forming complexes with polyphenols to reinforce cell walls [ 18 , 19 , 20 , 21 ]; for example, wheat ( Triticum aestivum L.) under cadmium (Cd) stress [ 22 , 23 ] and thermal stress [ 24 ], and rice ( Oryza sativa L.) under drought [ 25 ]. Furthermore, developing accessible methodologies to obtain materials that will serve as Si sources is highly desirable.…”

“…For example, the application of glass waste, a material easily found in landfill sites and used as silicon microparticle powders (SiMPs), becomes a simple approach that only requires grinding and sieving glass waste. Therefore, considering that seeds of M. oleifera are responsive to light [ 16 ], especially monochromatic red light [ 2 ], the irradiation of this type of light during seed priming could potentialize the stress-mitigating effect of SiMPs on plants.…”