Virus Induced Gene Silencing of prolyl-4-hydroxylase Induce alteration in Plant Growth

Prolyl 4-hydroxylases (P4Hs) belong to the family of 2-oxoglutarate-dependent dioxygenases and catalyze the formation of 4-hydroxyproline, requiring 2-oxoglutarate and O2 as co-substrates and Fe as a co-factor. Nine putative P4Hs have been identified up to now in the tomato genome. A reverse genetics approach, Virus-Induced Gene Silencing, was used to silence two P4Hs, P4H3 and P4H8. Transient silencing of P4H3 and P4H8 altered tomato plant growth. P4H3and P4H8-VIGS plants had shorter stems, reduced fresh weight and smaller leaves. The effect of VIGS application in different plant organs such as root, shoot, and root fresh weight, shoot fresh weight, leaves area were analyzed. Linear correlation was measured by calculating the Pearson correlation coefficiency in order to see if there are correlations between these variables. These results indicate that P4H3 and P4H8 play a significant role in tomato plant growth and VIGS is a useful tool to study the function of tomato gene families such as P4Hs in growth and development, and elucidate, in the long run, the physiological significance of substrate-proteins such as hydroxyproline-rich glycoproteins. Key word: prolyl-4-hydroxylase, plant growth, correlation, regression