Cytokinins antagonize the jasmonates action on the regulation of potato (Solanum tuberosum) tuber formation in vitro

Abstract

The effects of jasmonic acid (JA) and methyl jasmonate (MeJA) on potato (Solanum tuberosum L.) tuberization were studied in relation to cytokinins using single-node cuttings (SNCs) in vitro. In three potato cultivars differing in maturity levels, JA or MeJA (0.0, 2.5, 5.0, 7.5 and 10.0 lM) action was examined with N 6 -benzyladenine (BA: 0.0, 22.0 and 44.0 lM) under optimum tuber-inducing treatment with 80 g L -1 sucrose. Although jasmonates had a stimulatory role in root growth from SNCs, BA inhibited the root growth and antagonized the jasmonates action on root growth promotion. There was a strong inhibitory effect of BA on stoloniferous shoot growth, and in combination with jasmonates it could exert a much pronounced inhibitory effect. Jasmonates did not have any role in tuber induction in terms of tuber number and sourcesink coordination (harvest index), rather their effects were counteracted in the presence of 22.0 lM BA in early cultivar. However, they had a promoting effect on tuber growth after induction in early cultivar, possibly due to its lower levels of endogenous gibberellins.Cytokinins detrimentally affected the tuber growth, and antagonized the jasmonates action irrespective of the maturity levels of the cultivars. It could, however, increase the tuber dry matter concomitant with a higher accumulation of starch. The promoting effect of jasmonates on tuber dry matter and starch accumulation was apparent only in early cultivar. There were significant interactions between cytokinin and jasmonates for accumulation of reducing and total sugars in tubers. The results show that exogenous cytokinins antagonize the jasmonates action, and the correlated effects of these two growth hormones interact with the maturing time of the cultivar during potato tuber formation in vitro.

Endogenous cytokinin dynamics in micropropagated tulips during bulb formation process influenced by TDZ and iP pretreatment

“…These PGRs play crucial roles in regulating diverse plant development and physiological processes, including cell proliferation and differentiation, seed germination, apical dominance, flower and fruit development, leaf senescence, and transduction of nutritional signals. However, little is known about their roles in storage organ formation (Sarkar et al 2006;Malkawi et al 2007). Naturally occurring CKs are adenine derivatives carrying an isoprene-derived or aromatic side chain at the N 6 -amino group.…”

“…Considering all the acquired data, we postulate that CKs are heavily involved in the induction of tulip bulb formation, as in potato tuber formation (Donnelly et al 2003;Sarkar et al 2006;Malkawi et al 2007). The transient increase in CK contents could promote formation of scale primordia of the future bulbs.…”

Tracing the role of sucrose in potato microtuber formation in vitro

“…An increasing concentration of sucrose results in an increased percentage and earliness of tuberization (El-Sawy et al, 2007;Wattimena, 1995) of induced tissue. According to Momena et al (2014) and Sarkar et al (2006), BAP has a crucial role in determining the size of microtubers, because the growth of microtubers is stimulated by a high sucrose concentration with low nitrogen. High levels of carbohydrates in the form of sugars and starch favor the formation of storage organs such as tubers, whereas high nitrogen levels are known to promote shoot growth (Aksenova et al, 2012;Podwyszyĕska, 2012;Koda and Okazawa, 1983).…”

Evolutionary History of the GH3 Family Based on 48 Sequenced Plants and Identification of Jasmonic Acid-Relate GH3 Genes in <em>Solanum tuberosum</em>

“…The tissue culture seedling was treated by 10 -5 M MeJA [31,32] and collected materials treated in 4 different time periods. The StGH3 group I genes were studied the expression changing in these treatments ( Figure 6A, Table S3).…”