*Article* **Hydropriming and Osmotic Priming Induce Resistance against** *Aspergillus niger* **in Wheat (***Triticum aestivum* **L.) by Activating** *β-1, 3-glucanase, Chitinase,* **and** *Thaumatin-like Protein* **Genes**

**Summia Gul 1, Amjad Hussain 2, Qurban Ali 3, Intikhab Alam 4, Rana M. Alshegaihi 5, Qinglin Meng 6, Wajid Zaman 7, Hakim Manghwar 8,\* and Muhammad Farooq Hussain Munis 9,\***


**Abstract:** Priming is used as a method to improve plant growth and alleviate the detrimental effects of pathogens. The present study was conducted to evaluate the effects of different priming methods in the context of resistance to *Aspergillus niger* in wheat (*Triticum aestivum* L.). Here, we show that different priming treatments—viz., hydropriming, osmotic priming, halopriming, and hormonal priming techniques can induce disease resistance by improving the biochemical contents of wheat, including chlorophyll, protein, proline, and sugar. In addition, physiological parameters such as root length, shoot length, fresh and dry root/shoot ratios, and relative water content were positively affected by these priming methods. In essence, hydropriming and osmotic priming treatments were found to be more potent for enhancing wheat biochemical contents, along with all the physiological parameters, and for reducing disease severity. Hydropriming and osmotic priming significantly decreased disease severity, by 70.59–75.00% and 64.71–88.33%, respectively. RT-PCR and quantitative real-time PCR analyses of potentially important pathogenesis-related (PR)-protein genes (*Thaumatin-like protein* (*TLP*), *chitinase,* and *β-1,3-glucanase*) in primed plants were evaluated: *β-1,3-glucanase* was most highly expressed in all primed plants; *Chitinase* and *TLP* exhibited higher expression in hormonal-, halo-, osmotic-, and hydro-primed plants, respectively. These results suggest that the higher expression of *β-1,3-glucanase, TLP*, and *chitinase* after hydropriming and osmotic priming may increase disease resistance in wheat. Our study demonstrates the greater potential of hydropriming and osmotic priming for alleviating stress caused by *A. niger* inoculation, and enhancing resistance to it, in addition to significantly improving plant growth. Thus, these priming methods could be beneficial for better plant growth and disease resistance in other plants.

**Keywords:** wheat; priming; *Aspergillus niger*; qRT-PCR; wilting; *TLP*; *chitinase*; *β-1,3-glucanase*
