Nitric oxide promotes in vitro organogenesis in Linum usitatissimum L.

Abstract

The effects of nitric oxide (NO) on caulogenesis, shoot organogenesis and rhizogenesis from hypocotyl explants of Linum usitatissimum were investigated. Exogenously supplied NO donors, 5 lM sodium nitroprusside (SNP), 2 lM S-nitroso-N-acetylpenicillamine (SNAP) and 2 lM 3-morpholinosydnonimine (SIN-1), significantly promoted shoot differentiation from the hypocotyl explants of L. usitatissimum excised from its in vitro raised seedlings. Potassium ferrocyanide, a structural analogue of SNP, lacking NO group, did not promote shoot organogenesis. Likewise, products of NO, NO À 2 and NO À 3 supplied as 5 lM NaNO 2 and 5 lM NaNO 3 did not enhance shoot differentiation. Another source of NO, a mixture of sodium nitrite (SN) provided along with ascorbic acid (AsA), also caused significant promotion in the average number of shoots per responding explant. SNP also augmented the rhizogenic response of the microshoots in terms of percentage of responding explants, number of roots per responding explant and average root length. The NO scavengers, 2-(4-carboxy-phenyl)-4, 4, 5, 5-tetramethylimideazoline-1-oxyl-3-oxide (cPTIO) or methylene blue (MB), provided along with SNP, SNAP, SIN-1 or SN ? AsA, at concentrations equimolar to the optimum concentration of the donors, reversed the promotory influence, thereby, confirming the role of NO in promotion of in vitro morphogenesis. However, NO scavengers individually did not affect the observed morphogenic processes. Morphological and histological studies of hypocotyl segments cultured on BM or BM ? SNP for 4, 8 and 12 days demonstrated that SNP enhanced shoot differentiation by inducing a higher number of shoot primordia, each of which develops into a single shoot.

Stimulatory and period-specific effect of nitric oxide on in vitro caulogenesis in Albizzia lebbeck (L.) Benth.

“…To conclude, the present paper on A. lebbeck, a tree legume, affirms the role of NO in in vitro caulogenesis reported recently in Linum usitatissimum, an herbaceous plant (Kalra and Babbar 2010). This extends the versatility of NO molecule by confirming its effect on caulogenesis of two taxonomically divergent taxa.…”

“…cPTIO, when added alone, did not affect the caulogenic response. This observation seemingly suggests that there is no role of endogenous NO in in vitro caulogenesis of A. lebbeck, similar to what was observed with the caulogenic response of Linum (Kalra and Babbar 2010).…”

“…Further narrowing of the range of concentrations of SNP to 1-5 lM, with increment of 1 lM, revealed the stimulatory effect of 3 and 4 lM on the caulogenic response. The enhancement was only in terms of the number of shoots per responding explants, with 4 lM being the optimum (Table 1) as was also observed with explants of Linum usitatissimum (Kalra and Babbar 2010).…”

“…Its involvement has been shown in seed germination, hypocotyl elongation (Beligni and Lamatina 2000), stomatal movements (Desikan et al 2004;Distéfano et al 2008), flowering (He et al 2004;Khurana et al 2011), xylem differentiation (Gabaldón et al 2005), senescence (Leshem and Haramaty 1996), and rhizogenesis (Pagnussat et al 2002;Lanteri et al 2008). Recently, we have reported the promotory effect of NO on in vitro caulogenesis in Linum usitatissimum, an herbaceous plant (Kalra and Babbar 2010). The present work reports stimulatory effect of NO on in vitro caulogenic response of Albizzia lebbeck, a leguminous tree.…”

The effects of reactive nitrogen and oxygen species on the regeneration and growth of cucumber cells from isolated protoplasts

“…The effects of SNP on callus induction and shoot regeneration were demonstrated to be reversed by the NO scavenger cPTIO (Xu et al 2009). Various NO donors were shown to enhance the shoot differentiation of hypocotyl explants of Linum usitatissimum by inducing a higher number of shoot primordia (Kalra and Babbar 2010).…”