# Bacterial Indole-3-Acetic Acid Influences Soil Nitrogen Acquisition in Barley and Chickpea
## 2 Results
### Klebsiella Improves Shoot Phenotype and Biochemical Profiling

Table 1: Measurements of root morphology traits in barley and chickpea plants. Four structural traits, shoot fresh weight (SW), shoot dry weight (SDW), shoot length (SL), and grain weight (GW), were measured. Here, GW was a crucial parameter reflecting the yield of a crop. It was measured as grain weight (g) per pod. The response was highly significant in _K.p._ SSN1 and _K.q._ SGM81 treatment in both plant varieties. Amongst all, _K.p._ SSN1 treatment showed the highest SL, SW, SDW, and GW, irrespective of monocot or dicot host plant (Figure 2). _K.p._ SSN1 resulted in 181.7% and 198% increase while _K.q._ SGM81 resulted in 174% and 155.2% increase in GW in barley and chickpea, respectively, over control plants. Compared to control plants, _K.o._ M5a1 resulted in 100% higher barley GW and 57.6% higher chickpea GW. Effect of _\(\Delta\)nifH_ inoculation was non-significant on SDW of chickpea and on GW of both barley and chickpea. Next, we examined several biochemical characteristics of shoot, chlorophyll content (Cl), protein content (PR), nitrate reductase activity (NR), nitrate (NT) concentration, and total aboveground nitrogen (ABN). To study biochemical characteristics of plant post-uprooting, it was washed and was air-dried or kept fresh as required. Table 2 represents the results of all biochemical traits. In comparison to control plants, content of all parameters was improved in plants treated with wild type _Ikelsiella_ strains. For Cl, _K.p._ SSN1 showed 41.7% and 106.2% higher content than control in barley and chickpea, respectively, also being the highest among all other treatments. Estimation of total PR revealed that in barley, the highest PR content was in _K.p._ SSN1-treated plants, whereas in chickpea, _K.q._ SGM81 resulted in the highest protein with 51% increment compared to control. NR enzyme activity of _K.p._ SSN1 and _K.q._ SGM81-treated barley was almost similar. In chickpea, _K.o._ M5a1-treated plants resulted in 64.4% higher NR activity, which also was the highest among all other chickpea treatments. The highest NT was quantified in _K.p._ SSN1 plants of both varieties followed by _K.q._ SGM81 in barley and _K.o._ M5a1 in chickpea. Lastly, _K.q._ SGM81 resulted in the highest plant nitrogen in barley and _K.p._ SSN1 in chickpea, as shown in Table 2. The _\(\Delta\)nifH_ treatment failed to show any significant increase in the biochemical content above control plants. This demonstrates the failure of the _\(\Delta\)nifH__Klebsiella_ in promoting plant growth. The improvement in all the biochemical traits in _K.p._ SSN1 and _K.q._ SGM81, but not _K.o._ M5a1, clearly demonstrates that a coupled effect of root growth-promoting traits (auxin production) and nitrogen-fixing ability of _K.p._ SSN1 and _K.q._ SGM81 is more vital than nitrogen-fixing ability alone of _K.o._ M5a1. Collectively, from the above results, we infer that _Ikelsiella_ spp. contributed towards higher yield and improved biochemical characteristics, specifically those related to nitrogen accumulation or/and mobilization in barley and chickpea plants. Figure 2: Effect of inoculation on barley and chickpea shoot traits from left to right. Shoot traits include shoot length, shoot fresh weight, shoot dry weight, and grain weight. Bars represent mean values of replicates. Error bars represent standard error from the mean (\(n=6\)).