Dark Septate Endophytic Fungi Increase Green Manure-15N Recovery Efficiency, N Contents, and Micronutrients in Rice Grains

Abstract

An understanding of the interaction between rice and dark septate endophytic (DSE) fungi, under green fertilization, may lead to sustainable agricultural practices. Nevertheless, this interaction is still poorly understood. Therefore, in this study, we aimed to evaluate the accumulation of macro- and micronutrients, dry matter, and protein and N recovery efficiency from Canavalia ensiformis (L.)-15N in rice inoculated with DSE fungi. An experiment under greenhouse conditions was conducted in a randomized complete block design comprising split-plots, with five replicates of rice plants potted in non-sterilized soil. Rice (Piauí variety) seedlings were inoculated with DSE fungi, A101 and A103, or left uninoculated (control) and transplanted into pots containing 12 kg of soil, which had previously been supplemented with dry, finely ground shoot biomass of C. ensiformis enriched with 2.15 atom % 15N. Two collections were performed in the experiment: one at 54 days after transplanting (DAT) and one at 130 DAT (at maturation). Growth indicators (at 54 DAT), grain yield, nutrient content, recovery efficiency, and the amount of N derived from C. ensiformis were quantified. At 54 DAT, the N content, chlorophyll content, and plant height of inoculated plants had increased significantly compared with the control, and these plants were more proficient in the use of N derived from C. ensiformis. At maturation, plants inoculated with A103 were distinguished by the recovery efficiency and amount of N derived from C. ensiformis and N content in the grain and shoot being equal to that in A101 inoculation and higher than that in the control, resulting in a higher accumulation of crude protein and dry matter in the full grain and panicle of DSE-rice interaction. In addition, Fe and Ni contents in the grains of rice inoculated with these fungi doubled with respect to the control, and in A103 inoculation, we observed Mn accumulation that was three times higher than in the other treatments. Our results suggest that the inoculation of rice with DSE fungi represents a strategy to improve green manure-N recovery, grain yield per plant, and grain quality in terms of micronutrients contents in cropping systems with a low N input.

Effects of Dark Septate Endophytes on the Performance of Hedysarum scoparium Under Water Deficit Stress

“…The ability of DSE fungi to promote plant growth under water stress conditions may be related to the increased C and N absorption, as well as to the enhanced activities of antioxidant enzymes. Vergara et al (2018) have reported that increased N absorption by tomato plants was in response to inoculation with DSE isolates—inoculated plants exhibited higher dry weight than non-inoculated plants when supplied with organic N. Similarly, in our study, Phialophora sp. and Leptosphaeria sp.…”

“…As important root endophytes, DSE have been reported to have positive ecological roles in plant growth and nutrient uptake (Wu et al, 2010; Newsham, 2011; Surono and Narisawa, 2017; Vergara et al, 2018). They also provide increased plant resistance to a wide range of environmental stressors (Andrade-Linares et al, 2011; Likar and Regvar, 2013; Su et al, 2013; Berthelot et al, 2017; Santos et al, 2017; Zhang et al, 2017; Jin et al, 2018).…”

Angiosperm symbioses with non‐mycorrhizal fungal partners enhance N acquisition from ancient organic matter in a warming maritime Antarctic

“…DSEs are widespread in plant roots in a range of ecosystems (Jumpponen 2001;Newsham et al 2011), but there has been limited identification of their roles in plant nutrient acquisition to date, with some appearing to have negative effects on plant hosts (Jumpponen 2001;Upson et al 2009;Newsham 2011;Vergara et al 2018). Consequently, it remains unknown whether symbioses with DSEs are widespread facilitators of nutrient acquisition.…”

Antagonism potency of dark Septate endophytes against Pyricularia oryzae for improving health of rice plants

“…Endophytes fungi can stimulate plant canopy growth and have a higher wet weight than controls (Syarif et al, 2014). Vergara et al (2018) stated that dark septate endophytes fungi could access carbon, nitrogen, and phosphorus from rhizospheres and deliver them to the host. In-plant tissue, endophytes will actively protect plants directly or indirectly.…”