Polyamines and Flavonoids: key compounds in mycorrhizal colonization of improved and unimproved soybean genotypes

SALLOUM MARIA SORAYA ; MENDUNI MARIA FLORENCIA ; BENAVIDES PATRICIA ; LARRAURI MARIANA; LUNA CELINA MERCEDES ; SILVENTE SONIA

SYMBIOSIS

SPRINGER

Lugar: Berlin; Año: 2018

0334-5114

We tested the effects of flavonoids/phenols and polyamines (PAs) in arbuscularmychorrizal fungi from roots of improved (I-1) and unimproved (UI-4) soybeangenotypes. After 20 days of well watered conditions, roots of mychorryzal plants of UI-4 genotype had greater amount of total flavonoids and phenols, while in I-1 genotype no differences were observed between roots of mychorryzal and non mychorryzal plants. In spite that exogenous application of flavonoids led to an increase in root colonization and in the number of arbuscules and vesicles in both genotypes the I-1 genotype needs higher levels of flavonoids (150mg / l) to reach the percentage of mycorrhization achieved by UI-4 genotype without the exogenous addition of flavonoids. Mycorrhizal plants of both genotypes had higher endogenous polyamines content than non miycorrhizal plant, however, the highest content, especially of putrescine, was in U-4 mychorrhizal genotype.Furthermore, over our results show that down regulation of the GmADC transcriptwhich is involved in putrescine formation had a profound negative effect on mycorrhizal colonization and also affected the normal development of the plant. In addition,GmDAO silencing plants in which the ADC transcript is expressed, mycorrhyzal colonization is similar to control plant, thus supporting the important role that putrescine plays in mycorrhizal formation. Our results suggest that mycorrhizal colonization is affected by domestication since the improved genotype needs more amount of flavonoids and polyamines to reach the same percentage of colonization than unimproved soybean genotypes.