Azospirillum brasilense and cytidine as combination treatment to enhance drought resilience of peas

Researchers investigated the potential benefits of using the microbe Azospirillum brasilense in combination with cytidine or total pea seedling exudate to improve the drought resilience of pea plants. The study found that the treatment with cytidine, labeled as ACyt, was more effective than the seedling exudate treatment (AEx) in enhancing drought tolerance.

Peas treated with ACyt showed a 68.9% increase in drought tolerance compared to those treated with the inoculant alone (A). Moreover, the dry shoot weight of ACyt-drought plants was 30.7% higher than the untreated control group (NB). Additionally, drought recovery of ACyt plants was 21.6% better than that of the control group.

The researchers conducted a 16S rDNA analysis to understand the changes in the rhizosphere that accompanied the increase in drought tolerance and recovery. They found that the abundance of Azospirillum brasilense was 163% higher in ACyt plants during drought conditions compared to watered groups. The abundance of Azospirillum sp. was 954% higher in plants from the ACyt Drought group than those from the NB Drought group, suggesting that ACyt treatment may help protect pea plants from drought by increasing the abundance of Azospirillum.

The analysis of the 16S rDNA data set revealed that both ACyt Drought and AEx Drought groups experienced similar increases in Shannon and Pielou alpha-diversity indices compared to the NB Drought group. Both treatments also led to high abundances of Rhizobium and lower abundances of Massilia.

In conclusion, the combination treatment of Azospirillum brasilense and cytidine (ACyt) effectively enhanced drought tolerance and recovery in pea plants. Both treatments also increased alpha-diversity and modulated the rhizosphere, suggesting that ACyt could be a promising strategy for improving drought resilience in peas.