Insight into strigolactone hormone functions in plant parasitic weeds: a regulatory perspective

The strigolactones (SLs) are plants hormones that have multiple functions in architecture and development. The roles of SLs in shoot branching and stem secondary growth of autotrophic plants are established. SL is also involved in the interaction between root parasitic plants and their host plants. SLs are exudates by the root of the host plant in search of a fungal partner for symbiotic association, while parasitic plants utilize this facility to detect the host root. The first formed tubercle of Philapanhche, whose germinations are driven by host-derived SLs, exudates parasitic derived SLs (PSLs) and could encourages germination of the adjacent parasitic seeds, resulting in parasite cluster formation. The existence of aboveground spikes in clusters suggests an intriguing approach for increasing parasite population by amplifying PSLs, which result in massive parasitic seed germination. PSLs probably have a role in the increased branching of Broomrapes opposing the host plant, resulting in the parasites' clustered appearance aboveground. This review highlights the distinct roles of SLs and PSLs, and their potential role in host-parasitic interaction.

Determination of atmospheric heavy metals using two lichen species in Katni and Rewa cities, India.

A biomonitoring study was conducted to assess the levels of atmospheric heavy metal pollution in Katni and Rewa cities of Madhya Pradesh, state in central India. The Pyxine cocoes and Phaeophyscia hispidula, two epiphytic foliose lichen were used as bioindicators in the present study and seven metals (As, Al, Cd, Cr, Fe, Zn, Pb) were analyzed in naturally growing thallus. The concentrations of these metals was observed to be in higher range as maximum values of Al, Cd, Cr and Zn were reported from the lichen samples from Rewa city which was 561.8±2.4, 6.8±0.8, 35.2±1.4, 214.6±2.0 @g g-1 dry weight respectively. Whereas As, Fe and Pb were reported maximum in the lichen samples collected from Katni city areas with 33.4±0.05, 689.4±2.6, 13.3±0.5 @g g-1 dry weight respectively. However the accumulation of Cd and Pb from both the cities are more or less similar in concentration. The selectivity sequence of metals were Fe>Al>Zn>As>Cr>Pb>Cd in Katni city, and Al>Fe>Zn>Cr>As>Pb>Cd in Rewa city. The findings of this study indicates that extent of heavy metal pollution in the atmosphere of the two cities which may lead to adverse health affects.

Pollution monitoring with the help of lichen transplant technique at some residential sites of Lucknow City, Uttar Pradesh.

Samples of foliose lichen, Dirinaria consimillis (Fr.) Awasthi were transplanted at six residential sites of Lucknow city for monitoring the concentration of Cr, Zn, Pb, Cu and Cd metals at two vertical positions. The concentration of chromium and copper were more at the higher vertical position than the lower one. The maximum zinc was at lower vertical position than the upper one. Lead and cadmium were not detected in the present study.