Mitochondrial sense sHSP23.6 protein keeps photosynthetic electron transport during drought

Photosynthetic efficiency is influenced by extrinsic factors, such as water availability, which affects agricultural productivity. The adverse effects of stresses can be mitigated or even eliminated using improved plants. Small heat shock proteins (sHSPs) act as molecular chaperones and play vital roles in response to various stresses. Here we compared the effects of water deficit on photosynthetic activity of “Micro-Tom” tomato plants ( Solanum lycopersicum Mill) with different MT-sHSP23.6 level expression (sense and antisense) compared to the wild-type genotype, during floral induction period. At floral induction period (44 days after sowing), fifteen plants of each genotype were subjected to drought for 5 days. Chlorophyll a fluorescence transient, chlorophyll index and gas exchanges rates were performed on the first, third and fifth days of drought, and delayed fluorescence, modulated 820 nm reflection, proline concentration and growth parameters on the fifth day. The sense MT-sHSP23.6 plants showed better interconnection between the two photosystems, maintaining the electron flow, energy generation and chlorophyll index. Plants subjected to drought decreased carboxylation processes associated with non-stomatal factors and showed a reduction in leaf area and an increase in proline concentration. Plants of sense MT-sHSP23.6 tolerated water deficit conditions longer.