Interactive influences of intercropping by nitrogen on flavonoid exudation and nodulation in faba bean

Abstract

In order to address the question of how flavonoids affected root nodulation of faba bean in a wheat and faba bean intercropping system, we set up soil and hydroponic experiments comprising two cropping pattern treatments (intercropped and monocropped) and three nitrogen (N) supply treatments at the deficient (50% N), adequate (100% N), and excessive (150% N) levels with three replicates in a randomized complete block design. Across the three N treatments and two experiments, it was frequently observed that intercropping increased but N fertilization decreased the nodule number and nodule dry weight of faba bean. Six types of flavonoids were detected in the faba bean root secretion, but only genistein, hesperetin, and naringenin often had significant correlations with the nodule number and nodule dry weight. Intercropping increased faba bean root secretions of genistein, hesperetin, and naringenin compared to monoculture only at the deficient and adequate N supply levels. The differences in flavonoids of faba bean caused by the intercropped patterns, N supply levels, and their interactions were mainly significant at flowering stage. In conclusion, interspecies and N supply interactively altered the contents and proportions of flavonoids in faba bean root exudations under wheat and faba bean intercropping. These findings provide insight into flavonoids-nodule-yield interactions in cereal and legume intercropping systems.

Increased Nodular P Level Induced by Intercropping Stimulated Nodulation in Soybean Under Phosphorus Deficiency

“…Then, improved nodulation of soybean in intercropping under P deficient condition facilitated the growth of soybean and neighbouring maize (Table .1). Our results were in line with other previous studies on legume/cereal intercropping systems such as faba bean/wheat [24] , faba bean/maize [22] and pea/maize [23] in terms of nodulation and N 2 fixation.…”

“…A large number of results derived from field and pot experiments have proved that intercropping of legume and cereal could enhance the efficient utilization of phosphorus and yield through interspecific facilitation, even under phosphorus deficient conditions [18][19][20][21] . Additionally, evidences had accumulated recently that the practice of intercropped legume with cereal promoted the nodulation and N 2 fixation of legume by interspecific facilitation, and resulted in increased N uptake of associated cereal [22][23][24] . Considering the interspecific facilitation, we hypothesized that P level in nodules of legume under P stressful environment would be stimulated by intercropping.…”

Determination of the Effect of Co-cultivation on the Production and Root Exudation of Flavonoids in Four Legume Species Using LC–MS/MS Analysis

“… 29 These results are consistent with the findings from previous experiments conducted both in soil and hydroponic systems, showing that co-cultivation between cereal and legumes significantly increased the concentration of flavonoids in legume root exudate and promoted nodulation in legumes. 24 , 36 Li et al, 2009, reported that soil nitrogen deficiency could stimulate the biosynthesis of nod-inducer flavonoids and regulate their release into the root zone through the mechanism known as negative feedback regulation of nitrogen. 35 When legumes are used in intercropping systems with a cereal, rhizosphere N availability decreases during the first growing stages because of the stronger competition of cereals for nutrients.…”

“…Many studies revealed that interactions between plant species depend mainly on resource competition, 4 , 24 but there is increasing evidence showing involvement of allelochemicals. 37 , 38 Also, when optimal nutritional conditions occur, plants sense and respond to neighboring plants’ roots by changing the chemical profile of their root and root exudates.…”

Role ofGlycine maxin improving drought tolerance inZanthoxylum bungeanum

“…For example, legume (Fabaceae) crops may represent such key species, because they are known to be important in agroecosystem productivity and stability (Spehn et al, 2002). Normally, leguminous crops fix nitrogen (N) through symbiotic azotobacteria (Mosier, 2002;Yingchao et al, 2019) and provide additional nutrients to nearby crops (Chu, Shen & Cao, 2004;Xin-Ping Chen et al, 2011), and as a consequence, leaf nitrogen concentration in neighboring crops is affected (Temperton et al, 2007). However, drought negatively affects symbiotic nitrogen fixation by leguminous crops, through reduced phloem flow that facilitates nitrogenase activity in nitrogenated nodules (Marino et al, 2007;Serraj, Sinclair & Purcell, 1999).…”