Agriculture Reference
In-Depth Information
10.6 BACTERIAL PHYTOPATHOSYSTEMS INFLUENCED BY
CLIMATE CHANGE
Continuous cultivation of an agricultural plant spp. (often symbolized as
variety) introgressed with mono resistance (R) gene may be ineffective at
increased temperature. High temperature reduces effectiveness of R-gene
and therefore, makes complicate the R-gene mediated defense mechanism
against the phytopathogens. However, an R-gene ( Xa7 ) for Xanthomonas
oryzae pv. oryzae in rice performs better under increased temperature but
other R-genes are not (Webb et al. , 2010). Increased multiplication of X.
campestris pv. undulosa in wheat was noticed under high temperature
(25ºC) but at lower temperature (15ºC) even symptom was not produced
(Duveiller and Maraite, 1995). Against a few insect vectors temperature
has been reported as one of the factors that alter the patterns of gene ex-
pression under defense signaling pathways. Elevated CO 2 concentration
does not favor the bacterial multiplication in the host tissue. Lower bacte-
rial count of X. campestris pv. pelargonii was estimated in leaves of gera-
nium under increased level of CO 2 concentration (Jiao et al., 1999).
Apart from pathogenic spp. of bacteria, few beneficial bacteria act ac-
cording to the temperature exposure, which influences several phytopa-
thosystems. The bioremediation bacterium Pseudomonas putida grows
optimally with a wide range of temperature (4 to 30ºC) but the lower tem-
perature (below 10ºC) helps to express of at least 266 genes involving en-
ergy metabolism and assist other cellular functions (Fonseca, 2011). How-
ever, a strain of the same bacterial sp. tolerates high temperature (40ºC)
and performs well under drought areas (Srivastava et al., 2008).
10.7 VIRAL PHYTOPATHOSYSTEMS INFLUENCED BY CLIMATE
CHANGE
Viruses are severe in subtropical and tropical region (Thresh, 2006) and
in organic cultivation or protected systems (Pappu et al., 2009; Jones,
2004). Unlike other pathogens viruses are reported to infect wild relatives
of main host and create most alarming situation to the biodiversity (Jones,
2009). This affects the environment for both micro and macrolevel. Vi-
ruses express their symptom under elevated temperature. Higher tempera-
ture increases susceptibility to virus infection under artificial inoculation
 
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