Xylem-phloem cell area aid in salinity tolerance of tomato plant

Salinity lowers xylem-phloem flow, resulting in less carbon exchange at the leaf level, less water uptake by roots, and less carbohydrate transport. It is hypothesized that the xylem-phloem cell area influences salt tolerance. In the current study, eight tomato genotypes, viz. Nadir, Nagina, Naqeeb, IQS-7101, Roma, Pakit, Big Beef, and Rio Grande, were exposed to three different NaCl levels, i.e., stress 50 mM (mild salt stress), 100 mM (moderate salt stress), and 150 mM (severe salt stress), as well as a control treatment. The trial followed a completely randomized design. Data were collected on 24 distinct morphological, anatomical, physiological, and biochemical characteristics. Significant differences in all attributes were observed across four treatments. Under severe saline stress, the Nagina and Naqeeb plants produced more fruit and leaves. These genotypes exhibited greater xylem and phloem cell areas compared to other genotypes. This supports our hypothesis that these cells are involved in salt tolerance. The correlation analyses also revealed a positive relationship between xylem (XCA) and phloem cell area (PCA) with root fresh weight (RFW), root dry weight (RDW), root length (RL), shoot length (SL), number of green leaves per plant (NGLP), and number of fruits per plant (NFP) under mild and severe salinity stresses.